Tether

Abstract: Tether is a crypto token based on top of Bitcoin and Ethereum’s blockchains, the value of which is pegged to the US dollar by centralised USD reserves. There is scepticism about Tether, with accusations that the system is not backed by sufficient reserves. We think that this Tether scepticism is mostly focused on the wrong issue. We have found possible evidence in published financial data that the impact of Tether is visible in Puerto Rico’s banking system. Tether is likely to be, or is already, encountering problems related to regulation and we think this should be the primary long-term concern for Tether holders.

About Tether

Tether is a scheme that allows fiat currencies such as the US dollar to be used on the Bitcoin (and Ethereum) blockchain. The abstract of the Tether white paper explains:

A digital token backed by fiat currency provides individuals and organizations with a robust and decentralized method of exchanging value while using a familiar accounting unit. The innovation of blockchains is an auditable and cryptographically secured global ledger. Asset-backed token issuers and other market participants can take advantage of blockchain technology, along with embedded consensus systems, to transact in familiar, less volatile currencies and assets. In order to maintain accountability and to ensure stability in exchange price, we propose a method to maintain a one­-to-­one reserve ratio between a cryptocurrency token, called tethers, and its associated real­world asset, fiat currency. This method uses the Bitcoin blockchain, proof of reserves, and other audit methods to prove that issued tokens are fully backed and reserved at all times

The Tether token therefore exists on top of the Bitcoin and Ethereum blockchains, with around 97% and 3% of its tokens existing on each chain respectively. On Bitcoin, its tokens exist similarly to coloured coins and use the Omni layer, whose protocols interpret extra meaning from some surplus Bitcoin transaction data — for example, the creation or transfer of Tether.

The primary use case of Tether appears to be financial speculation, with many exchanges allowing their customers to buy and sell Tether in exchange for crypto tokens such as Bitcoin. Currently, around 2.2 billion Tether, representing US$2.2 billion, exist. As the chart below illustrates, about 85% of Tether holders are known, with the largest holders being the biggest crypto token exchanges. There is likely to be some mechanism by which these large holders can redeem Tether directly for USD, which we speculate on at a later point in this report.

Tether owners in February 2018 listed in millions of USD. (Source: Tether rich list, Tether transparency report)

The Tether hack

It appears as if the Tether treasury wallet was hacked in November 2017. US$31 million was stolen and sent to an external Bitcoin address, where it remains in quarantine. On 21 November, Tether released a forked client of OmniCore. This froze the stolen funds and was essentially a hardfork of the Omni layer. Since the Tether company backs the Tether token with real USD, Tether users had to upgrade, since Tether would obviously only back the tokens on their chosen side of the fork. As Tether put it:

We strongly urge all Tether integrators to install this software immediately.

The hacking incident demonstrated that Tether is effectively in complete control of the ledger, as they can force a hardfork at will and reverse any transaction — although there may not have been any doubt about Tether’s control beforehand. This raises the question of why Tether bothers to put the database on the Bitcoin and Ethereum blockchains at all — it would be far cheaper for Tether to create its own public database without needing to pay fees to the miners. Although the Tether company was and is able to freeze funds, the process is technically difficult and time consuming, as it requires new software to be written and released and for all Tether exchanges to upgrade.

Who controls Tether?

The Tether “About us” page only appeared between 5 December 2017 and 7 December 2017, and it revealed that Tether had the same management team as the Bitfinex exchange, as the table below illustrates. This is approximately when Tether is said to have received a subpoena from the US Commodities Futures Trading Commission (6 December 2017). Prior to this point, Tether did not disclose its management team — on the website, at least — although it was widely believed that Bitfinex was behind Tether. The timing appears to suggest that the subpoena may have prompted the greater transparency.

Bitfinex Senior Team Tether Team
JL van der Velde (CEO) JL van der Velde (CEO)
Giancarlo Devasini (CFO) Giancarlo Devasini (CFO)
Philip Potter (CSO) Philip Potter (CSO)
Stuart Hoegner (general counsel) Stuart Hoegner (general counsel)
Matthew Tremblay (chief compliance officer) Matthew Tremblay (chief compliance officer)
Paolo Ardoino (CTO)
Chris Ellis (community manager)

Tether and Bitfinex have essentially the same management team. (Source: Tether, Bitfinex)

The Paradise Papers, released in November 2017, revealed that Bitfinex’s CFO and CSO are owners and directors of Tether respectively. There was already little doubt about the link between Tether and Bitfinex prior to full disclosure on Tether’s website.

Tether management and owners. (Source: Paradise Papers)

Some think that Tether may have previously implied that Bitfinex doesn’t control Tether. For example, Craig Sellars, a Tether founder and advisor — and a former CTO of Bitfinex — stated on Reddit in spring 2017:

Bitfinex is a customer of Tether. If Bitfinex wants more USD, they make a request to Tether, just like all other Tether customers. Tether waits for USD to show up, and when it does, creates the necessary tethers and credits Bitfinex.

That comment left much open to interpretation but certainly did not explicitly state that Bitfinex does not control Tether. In this comment, a month prior to the above one, Sellars specifically states that he and Bitfinex CSO Phil Potter were discussing how to improve Tether. Sellars was also open about his simultaneous involvements in Tether and Bitfinex, as his LinkedIn profile indicates:

  • April 2014 to present: Tether founder and advisor
  • January 2015 to May 2016: Bitfinex CTO
  • April 2014 to May 2016: Tether founder and CTO

We do not think there is evidence that Tether misled the public about Bitfinex’s involvement, which some have claimed.

The Tether audit

The Tether homepage states that:

Our reserve holdings are published daily and subject to frequent professional audits.

The accounting firm Friedman LLP (FLLP) published a report in September 2017 in which  it confirmed that the USD balances that Tether was supposed to hold. The report stated that as of 15 September 2017, a bank held $382,064,782 in an account in the name of Tether.

However, the report did not disclose the names of any of the banks nor did it mention the jurisdictions in which the banks operate. The report also stated that:

FLLP did not evaluate the terms of the above bank accounts and makes no representations about the Client’s ability to access funds from the accounts or whether the funds are committed for purposes other than Tether token redemptions.

In January 2018, Tether ended its relationship with FLLP and explained with this emailed statement.

We confirm that the relationship with Friedman is dissolved.  Given the excruciatingly detailed procedures Friedman was undertaking for the relatively simple balance sheet of Tether, it became clear that an audit would be unattainable in a reasonable time frame. As Tether is the first company in the space to undergo this process and pursue this level of transparency, there is no precedent set to guide the process nor any benchmark against which to measure its success.

The statement indicates that there is a lack of transparency and the audit processes appears inadequate, or at least inconsistent with the promises made on the Tether website. This  likely contributed to the rumors in the cryptocurrency community — for example, claims that Tether is a Ponzi scheme.

Lack of transparency does not necessarily indicate fraud

Tether allows its users to send and receive USD. Transactions cannot easily be blocked and users require no permission — although one notable exception to this is Tether requiring all users to upgrade to a new client in order to block transactions, which is the cumbersome process that occurred after the $31 million hack.

Tether also potentially allows users a degree of anonymity when making or receiving transactions. Its characteristics potentially make it attractive to criminals, just like Bitcoin. While those with the ability to issue and redeem Tether, such as exchanges, are required to go through approval and KYC processes, individual users can use Tether merely by generating a public/private key pair, again just like Bitcoin.

Regulators are unlikely to be particularly happy about this and banks are likely to consider Tether with scepticism. Tether also requires the use of a bank, to hold the USD reserves required to back Tether. Many banks are likely to approach Tether cautiously, and accepting Tether as a client may violate a bank’s compliance procedures such as rules meant to prevent money laundering.

Therefore, Tether may have a problem: either the company may try to conceal aspects of how Tether operates from the reserve bank or the company may need to find a bank with compliance procedures that are not as strict as those of the most prominent financial institutions. We suspect that Tether may have struggled to find appropriate banking relationships and may have had accounts with many banks in many jurisdictions as it tried to find the right partner. We believe this is likely to be the primary reason for the apparent lack of transparency, rather than a lack of USD reserves. The transparency that some Tether stakeholders seem to expect may not be possible in the financial sector when the underlying activity is not clearly authorized or regulated by the authorities.

The Bitfinex exchange may have revenues in excess of US$1 million per day during the recent crypto currency bubble (assuming 100,000 BTC volume per day, 0.1% commission, and a $10,000 BTC price). Even if Tether were experiencing problems, Bitfinex may have resources sufficient to bail out the system. This wealth may also remove some of the incentive to run a fraud or a Ponzi scheme of the type some of the Tether sceptics allege.

Financial data from Puerto Rico

Rumors have been circulating that Tether may have some link to the unincorporated American territory of Puerto Rico. We decided to analyse public financial data to look for signs of unusual activity or strong growth.

We noticed strong growth in the cash balance (and the deposit balance) in the International Financial Entities (IFE) banking category. This sharp increase in cash reserves could be related to Tether. It is also possible for this growth to be related to a non-Tether aspect of the crypto currency ecosystem — for example, plans to make Puerto Rico a crypto utopia.

The chart below compares the value of Tether issued versus the deposit balance for the IFE banking category in Puerto Rico. The match is far from perfect and we cannot draw any strong conclusion from the data. It will be interesting to see what figures the regulators in the region produce going forwards.

Puerto Rico’s IFE aggregate deposits versus Tether in millions of USD. (Source: IFE Accounts, BitMEX Research, Coinmarketcap)

In addition to the growth of the total cash balance, we noticed that the cash balance was growing as a proportion of total assets, as the chart below illustrates.

 Puerto Rico’s IFE aggregate cash as a proportion of total assets. (Source: IFE Accounts, BitMEX Research)

This kind of balance-sheet structure is unusual. Normally, banks lend most of their assets and only keep a small balance as cash. The table below shows a simplified typical structure of bank balance sheets.

Illustrative example of the balance sheets of a typical bank and a 100% reserve bank respectively. (Source: BitMEX Research)

Full-reserve banking results in a different balance sheet, which should be detectable by financial analysts even when looking at macroeconomic data. As of the end of September 2017, the ratio of cash to total assets for this category of financial institution in Puerto Rico rapidly climbed to over 70%. This may indicate the presence of full-reserve banking in the territory and that the practice is growing.

Full-reserve banking

Full-reserve banking (also called 100% reserve banking) is when a bank does not lend deposits but keeps all deposited funds either in the form of physical cash or electronically on deposit at a custody bank or the central bank. Full-reserve banking is a fringe concept in modern finance often associated with the Austrian School of economics and libertarianism (or even a Bitcoin type of philosophy). Full-reserve banking is said to make the financial system less susceptible to credit expansion, something Bitcoin is also said to be able to achieve. The main benefit of this is that it could make the economy less likely to experience business cycles, as we explained in our earlier piece.

Noble Bank

We looked at all the financial institutions in the IFE category in Puerto Rico, and identified two banks which claim to be full-reserve banks: Euro Pacific International Bank and Noble Bank International. Full-reserve banks are rare, so while we can’t rule out the existence of any others, it may be unlikely that any others are operating.

Extract from the list of registered IFEs in Puerto Rico. Noble is highlighted in red by BitMEX Research.(Source: Commissioner of Financial Insitutions of Puerto Rico)

Euro Pacific Bank is run by Peter Schiff, a well-known Austrian economist and Bitcoin sceptic. Due to this scepticism, we think it is unlikely that Schiff would become involved in a Bitcoin-related entity like Tether.

Noble Bank, however, is involved in the crypto space and therefore could be involved in Tether. Evidence of Noble’s involvement in cryptocurrency includes the following extract from a letter to the regulator that the bank sent in 2015:

Noble intend to operate an integrated financial market network for the trading, clearing, and settlement of real currency, Bitcoin and other digital currencies

Noble is also the bank that entered into a Bitcoin-related business partnership with Nasdaq in 2015. We suspect that the growth in reserves in this section of the financial services industry in Puerto Rico is related to Noble Bank and cryptocurrency, whether or not this involves Tether.

The founder and CEO of Noble Bank, John Betts, was also behind the 2014 Sunlot Holdings move to take over and potentially rescue MtGox. Sunlot was backed by Brock Pierce, one of the founders of Tether.

Of course, a previous professional relationship between the Noble Bank CEO and one of the Tether founders proves nothing, and the blockchain ecosystem is a small space so such connections are likely. We would like to emphasize that even if Noble Bank is the primary reserve bank of Tether, none of this is evidence that Noble Bank has done anything inappropriate or illegal.

In a Medium post, Noble describes how it lets “clients to create their own pools of credit” and explains the structure of this system with the following illustration.

(Source: Medium)

It is possible that the above model could be the underlying structure behind Tether, and this could explain how it is backed by US dollars. This would indicate the USD that back Tether are inside the Puerto Rican banking system with the reserves held by BNY Mellon, Noble’s custody bank, which is the largest custody bank in the world. If true, this would imply that Tether is not a Ponzi scheme, since the USD reserves are present and being reported to the authorities, and that the reserves may be relatively safe. Although, as we explain later in this report, this should not provide complete comfort for Tether holders in the long term.

Case studies

As we mentioned above, Tether has the following characteristics:

  • No permission is required to send or receive Tether.
  • Transactions cannot be easily blocked.
  • Tether users may be able to obtain a degree of anonymity.

These characteristics may make the system attractive for criminals and money launderers — and if criminal activity becomes too prevalent, the authorities may wish to shut the system down. This has already happened numerous times in the past, as the case studies below demonstrate. In a later report, we may dig into the history of these case studies in more detail.

Liberty Reserve (2006-2013)

Liberty reserve was a Costa Rica-based centralized digital-currency service that let users  send and receive USD-denominated payments over the Internet. Payments could be made using email addresses and there was no procedure to identify those using the system. In 2013, Costa Rican authorities closed the service, accusing the system of facilitating the laundering of US$6 billion of criminal proceeds in the indictment. The founder of the service was arrested and sentenced to prison. The BBC described the service as follows:

Cash could be put into the service using a credit card, bank wire, postal money order or other money transfer service. It was then “converted” into one of the firm’s own currencies – mirroring either the Euro or US dollar – at which point it could be transferred to another account holder who could then extract the funds.

GoldAge (1999-2006)

Prior to founding Liberty Reserve, the same founders ran GoldAge, a gold-based payment platform that was also shut down by the authorities. As the US Justice Department put it:

The defendants had transmitted at least $30 million to digital currency accounts worldwide since beginning operations in 2002. The digital currency exchanger, GoldAge, received and transmitted $4 million between January 1, 2006, and June 30, 2006, as part of the money laundering scheme.

e-Bullion (2001-2008)

e-Bullion was a centralized Internet-based gold-payment system. In 2008, the co-founder of the system was murdered. As a result, the US government confiscated the company’s assets and the system was shut down.

DigiCash (1994-1998)

Perhaps one of the most interesting of the centralised pegged-payment platforms was DigiCash. Developed by David Chaum, DigiCash had strong anonymity technology based on blind signatures built into the system. The platform resembled modern distributed anonymity-based tokens like Monero.

Although DigiCash was centralised, the operator was unable to obtain details about the transactions because everything was anonymous, and therefore the transactions themselves were, in a sense, fully censorship resistant. However, the company eventually failed and in 1998 filed for bankruptcy.

Censorship resistance has two sides: one, that transactions themselves cannot be blocked and the second being that the entire system cannot easily be shut down. The first is relatively easy to achieve though anonymity-based technology such as ring signatures, while the second is more challenging.

The US Justice Department lists other examples of shut-down Internet-based payment systems, including the following.

E-gold (1996-2007)

On April 27, 2007, a federal grand jury in Washington, D.C., indicted two companies operating a digital currency business and their owners. The indictment charges E-Gold Ltd., Gold and Silver Reserve, Inc., and their owners with one count each of conspiracy to launder monetary instruments, conspiracy to operate an unlicensed money transmitting business, operating an unlicensed money transmitting business under federal law, and one count of money transmission without a license under D.C. law. According to the indictment, persons seeking to use the alternative payment system E-Gold were only required to provide a valid Email address to open an E-Gold account–no other contact information was verified. The indictment is the result of a 2½-year investigation by the U.S. Secret Service with cooperation among investigators, including the Internal Revenue Service (IRS), the Federal Bureau of Investigation (FBI), and other state and local law enforcement agencies. According to Jeffrey A. Taylor, U.S. Attorney for the District of Columbia, “The defendants operated a sophisticated and widespread international money remitting business, unsupervised and unregulated by any entity in the world, which allowed for anonymous transfers of value at a click of a mouse. Not surprisingly, criminals of every stripe gravitated to E-Gold as a place to move their money with impunity.”

ShadowCrew

On June 29, 2006, Andrew [Mantovani] was sentenced to 32 months in federal prison for cofounding Shadowcrew.com, an international online discussion forum with more than 4,000 members, many of whom specialized in identity theft and fraud. Shadowcrew members sent and received payments for goods and criminal services through digital currencies. One indicted member, Omar Dhanani, operated an illegal currency exchange, providing members a money laundering service in digital gold by anonymously converting their illicit cash. Dhanani stated that Shadowcrew members used digital gold in order to avoid traditional banking systems. A yearlong investigation by the U.S. Secret Service led to the October 2004 arrest of 21 individuals in the United States, with several other arrests in foreign countries.

Western Express International Currency Exchange Company (2002-2005)

On February 22, 2006, Vadim Vassilenko, Yelena Barysheva, and Alexey Baryshev were indicted by the state of New York for operating an illegal check-cashing and money transmittal business from 2002 through 2005. Their company, Western Express International, acted as a currency exchanger, knowingly exchanging criminal proceeds for digital currencies. Through its web sites, Western Express actively solicited overseas clients in eastern Europe, Russia, and the Ukraine to operate illegally in the United States. Clients using fictitious, often multiple identities committed a variety of cyber crimes, such as reshipping, phishing, spoofing, and spamming. Items purchased with stolen credit card numbers were resold for digital gold, which was further laundered through Western Express. A total of $25 million flowed through the company’s bank accounts over the 4-year period, in violation of New York banking regulations.

Conclusion

History has shown that centralised systems with certain characteristics (censorship resistance or anonymous transactions) tend to get shut down by the authorities. Tether shares some of the same characteristics as these extinguished services so it may also attract criminals and ultimately suffer the same fate.

In our view, Tether has two choices:

  1. Reform the system to include KYC/AML procedures that allow the operator to easily block transactions or freeze funds. In order to do this, Tether may need to fundamentally change its technological architecture and perhaps leave the public blockchains. Essentially, Tether would just be turning into a traditional (or full-reserve) bank.
  2. Continue as is and risk being be shut down by the authorities at some point.

If Tether is shut down, there is a risk that some users may lose access to their funds, perhaps temporarily. We do not recommend holding Tether for the long term, but not for the reasons some of the sceptics typically pronounce. We think that criminal usage of Tether is likely to be relatively low because of the use of Tether for financial speculation, which is probably the system’s dominant use case. Furthermore, we have not found any evidence of criminals using Tether to launder funds. As it stands, we think an imminent shutdown is unlikely.

The case studies above illustrate the two angles to censorship resistance (individual transactions and the system as a whole) and what distributed crypto tokens need to achieve in order to be sustainable in the long run. If a payment system cannot block transactions, doesn’t require permission for use, or offers anonymous use, it will probably eventually be shut down. This could be just as true for systems like Tether and Ripple as it was for Liberty Reserve, E-gold, and DigiCash. A potential way around this is to try to build a distributed system that cannot be shut down (i.e., censorship resistance for the system as a whole).  Whether Bitcoin or other proof-of-work-based systems can achieve this is still unproven, in our view.

Disclaimer

Whilst many claims made in this note are cited, we do not guarantee accuracy. We welcome corrections.

A blockchain-specific defensive patent licence

Abstract: Although the impact of patents on society is debatable, they can have negative impact on the blockchain space. Opening patents up is potentially crucial to the blockchain industry. Unfortunately, however, technology innovators may need to obtain patent protection for defensive purposes. A defensive patent licence (DPL) may be able to protect the ecosystem from the harmful restrictions of patents or mitigate some of the risks. We explain some potential deficiencies and loopholes in the current DPL and take a look at a new, improved licence, a blockchain DPL (BDPL).

(Source: Mises Institute)

Patents in the blockchain space

The issue of intellectual property (IP) is somewhat controversial in the libertarian and blockchain communities. Although patents and copyrights are generally accepted by most, many libertarians regard these systems as unethical state-granted monopolies that impede economic prosperity. This negative view of IP is articulated by Stephan Kinsella in his article “Against Intellectual Property“, in which he describes a patent as follows:

A patent is a property right in inventions, that is, in devices or processes that perform a “useful” function. A new or improved mousetrap is an example of a type of device which may be patented. A patent effectively grants the inventor a limited monopoly on the manufacture, use, or sale of the invention. However, a patent actually only grants to the patentee the right to exclude (i.e., to prevent others from practicing the patented invention); it does not actually grant to the patentee the right to use the patented invention.  Not every innovation or discovery is patentable. The U.S. Supreme Court has, for example, identified three categories of subject matter that are unpatentable, namely “laws of nature, natural phenomena, and abstract ideas.” Reducing abstract ideas to some type of “practical application,” i.e., “a useful, concrete and tangible result,” is patentable, however.

Copyright, on the other hand, covers original works such as books, articles, movies, and computer programs. When it comes to the IP of blockchains or other technologies, patents seem to be more relevant than copyright, which applies more to works of art.

Whatever one thinks of the merits of patents, when it comes to assessing the efficacy of patents in the blockchain space, there are some specific considerations:

  1. A key feature of blockchains is their permission-less architecture, in which nobody has the ability to censor usage of the system (a.k.a. censorship resistance). If one patents a use or function in a blockchain-based system (such as a new transaction format), the patent holder and legal authorities may be unable to prevent its usage by others, potentially making patents unsuitable or unenforceable.
  2. A patent on a cryptocurrency mining technology could give the patent holder a competitive advantage over other miners. This could undermine the whole point of mining, which requires a degree of competition in order to be useful. If a miner or mining coalition achieves a significant proportion of the hashrate, they could censor some or all of the transactions, or even attempt to reverse transactions, potentially rendering the blockchain useless.

Therefore, although the efficacy of patents is debatable in general, many consider them negative with respect to blockchains and desire to avoid the usage of enforceable patents in the blockchain space altogether. Achieving this preferred outcome is not simple; it’s not sufficient for those who develop technology in this space simply to avoid patents. This approach would be vulnerable to so-called patent trolls who could patent these technologies at a later date and possibly hold hostage those blockchain businesses and users who use the patented technology. A form of protection against patent trolls is required.

The DPL

One such tool to prevent or mitigate the risks of patent trolls is the DPL. Companies already using this include the Internet Archive and Blockstream. By signing the DPL, these companies essentially allow any company or individual to use all of their patented technologies for free, as long as they also join the DPL. In order to join the DPL, one must commit to put all one’s respective patents inside the DPL and to not make an infringing patent claim against any DPL member. This effectively forms a club, which anyone may join, whose members need not worry about using the patents owned by any other member. The use of DPLs is purely defensive, and the more entities that join the DPL, the better it is for the blockchain community.

Problems with the DPL

We have spoken to some patent holders in the ecosystem as well as legal experts, and some have identified potential deficiencies within the DPL. The DPL is a first-draft attempt at this scheme and many seem to acknowledge that there is significant scope for improvement.

Potential DPL loopholes include:

  1. The DPL mentions the licence can be revoked if a member transfers a patent to a separate, non-DPL entity that does not abide by the terms of the DPL. However, this restriction only applies once member has joined the DPL. It is possible, in theory, for an entity to transfer patents to an associated company before joining the DPL. In this scenario, the new DPL member who transferred the patent could collude with the company who received it to engage in aggressive patent claims against other DPL members, while still being free to use other patents in the DPL.
  2. Although the DPL prevents members from enforcing their patents among other members, it does not prevent third parties from enforcing patents. A third party may restrict some DPL members from using a patent while licensing that same patent to other DPL members. If this occurs, as in the figure below, any DPL members obtaining the rights to use the patent could have an advantage over other DPL members, which is exactly what the DPL was set up to prevent.

Company H is not a member of the DPL but it licenses the use of its patented technology to DPL member company A while engaging in enforcement action against the other DPL members. This gives company A an advantage, while company A is still a valid member of the DPL. (Source: BitMEX Research)

The new BDPL

A proposed blockchain-specific DPL scheme, the BDPL, aims to improve on the DPL with amendments and additional terms that hope to correct the loopholes identified above. The BDPL still retains the core defensive properties of the original DPL, granting a licence to all members who join the BDPL.

This first loophole is fixed with an amendment to one of the terms in the licence. The original DPL merely prevents a member from making any non-defensive patent claim against another member. The new terms also prevent a member, “whether individually or in collusion with each other or with any other person”, from making a non-defensive claim. This stricter requirement may make the type of collusion mentioned above more difficult.

The second loophole is fixed by adding a new term to the licence. This is a requirement that specifies that the licence will be revoked if members use any patent licensed by a third party, when such a licence “is or is likely to be” enforced and restricted from use by another BDPL member. This should prevent a scenario such as the one illustrated above.

Conclusion

In our view, this new BDPL offers an improved, more robust alternative to the existing system. However, it is more onerous in some respects than the old scheme — for example, there are stricter requirements about making public notices. In addition, closing the circumvention loopholes requires a tradeoff: a BDPL member could be caught between a rock and a hard place if it licenses a crucial technology from a non-BDLP member who then begins enforcement action against other BDLP members without the knowledge of the licensee. Fixing this problem within the licence may not be possible, although mitigating this risk could be possible with additional licensing terms preventing aggressive action against other BDPL members.

Providing patent owners with more choices can only be beneficial and this new licence is a positive addition to the blockchain space. This scheme may be more robust and therefore more attractive to patent holders, while maintaining the defensive nature that can protect the ecosystem from the harmful effects of patents. We have spoken to patent owners who have indicated that they may prefer the BDPL to older schemes. While it would be beneficial were such defensive schemes to become popular, it is difficult to predict which, if any, will succeed.

We think the BDPL is both a significant improvement and more likely to be adopted than the DPL. If adopted, the BDPL could substantially benefit the ecosystem, mitigating one of the risks silently looming over the blockchain space.

 

The Ripple story

Abstract: In this piece, we briefly look over the history of Ripple and examine various disputes between the founders and partner companies, typically over control of XRP tokens. We then explore elements of the technology behind Ripple. We conclude that the apparent distributed consensus mechanism doesn’t serve a clear purpose, because the default behaviour of Rippled nodes effectively hands full control over updating the ledger to the Ripple.com server. Therefore, in our view, Ripple does not appear to share many of the potentially interesting characteristics crypto tokens like Bitcoin or Ethereum may have, at least from a technical perspective.


Jed McCaleb (left) joined Ripple in 2011. Chris Larsen (right) joined the company in 2012. (Source: BitMEX Research)

Introduction

On 4 January 2018, the Ripple (XRP) price reached a high of $3.31, an incredible gain of  51,709% since the start of 2017. This represented a market capitalization of $331 billion, putting Ripple’s valuation in the same league as Google, Apple, Facebook, Alibaba, and Amazon — the largest tech giants in the world. According to Forbes, Chris Larsen, the executive chairman of Ripple, owns 17% of the company and controls 5.19 billion XRP, worth around $50 billion at the time of the peak, making him one of the richest people in the world. Despite this incredible valuation, many of the market participants do not appear to know much about Ripple’s history or the technology behind it. In this piece, we provide an overview of the history of Ripple and look at some of its technical underpinnings.

History of Ripple

RipplePay: 2004 to 2012

Ryan Fugger founded a company he called RipplePay in 2004. The core idea behind the protocol was a peer-to-peer trust network of financial relations that would replace banks.


The RipplePay logo during that period of the company’s existence. (Source: Ripplepay.com)

RipplePay’s basic theory was as follows:

  • All banks do is make and receive loans. A bank deposit is a loan to the bank from the customer.
  • A payment from Bob to Alice in the traditional banking system is simply an update to their respective loan balances to the bank, with Bob’s loan to the bank declining slightly and Alice’s increasing slightly.
  • RipplePay held that one could replace banks by creating a peer-to-peer trust network in which individuals could directly loan each other, and alterations to these loan balances enable payments.
  • Payments, then, are simply updates to these loan balances, provided the system can find a path of relationships from the payer to the recipient.


In this example, the person on the far right side of the lineup makes a payment of $20 to the person on the far left. Although the payer and recipient do not directly trust each other, the payment transfers through a chain of IOUs forged of seven people who are linked by six trusted relationships. (Source: Ripple.com)

The network architecture is not dissimilar to the idea behind the Lightning Network, except with counterparty risk, something which Lightning avoids. In our view, this model is likely to be unstable and the trust networks are unlikely to be regarded as reliable — and therefore we are unsure of its efficacy. Either the system would centralise towards a few large banks and fail to be sufficiently different to the existing financial system or it would be liable to regular defaults. However, the current Ripple system is very different to this original idea.

At the start of 2011, Bitcoin was gaining some significant traction and began to capture the attention of Ripple’s target demographic. To some extent, Bitcoin had succeeded where Ripple had failed, building a peer-to-peer payment network with what appeared to be a superior architecture to Ripple. In May 2011, Jed McCaleb, an early Bitcoin pioneer, joined Ripple, perhaps to address some of these concerns.

McCaleb had founded the Mt. Gox Bitcoin exchange in 2010, which he sold to Mark Karpeles in March 2011. According to an analysis of the failure of Mt. Gox by WizSec’s Kim Nilsson, the platform was already insolvent, to the tune of 80,000 BTC and $50,000, in March 2011 when McCaleb sold it. Shortly after this, Ryan Fugger handed the reins of the Ripple project to McCaleb.

This video from June 2011 describes some of the philosophy and architecture of Ripple after McCaleb had joined the project:

OpenCoin: September 2012 to September 2014


The Ripple logo during the OpenCoin period. (Source: Ripple.com)

In 2012, McCaleb hired Chris Larsen, who remains on the board today as the executive chairman and whom the current website describes as a co-founder of Ripple. This marked the start of the OpenCoin era, the first of three name changes between 2012 and 2015. Larsen is the former chairman and CEO of E-Loan, a company he co-founded in 1996, took public in 1999 at the height of the tech bubble, and then sold to Banco Popular in 2005. Larsen then founded Prosper Marketplace, a peer-to-peer lending platform, which he left to join Ripple in 2012.

Larsen is not new to volatile prices and price bubbles. E-Loan experienced a peak-to-trough fall of 99.1% between 1999 and 2001. E-Loan’s IPO share price stood at $14 on 28 June 1999 before selling for $4.25 per share in 2005. (Source: Bloomberg)

To address the success of Bitcoin, Ripple now planned to allow Bitcoin payments on its network, potentially as a base currency for settlement. This period also marked the launch of the Ripple Gateway structure. The community realized that the peer-to-peer structure did not seem to work, with ordinary users unwilling to trust counterparties sufficiently to make the network usable for payments. To address this, Ripple decided to form gateways, large businesses that many users would be able to trust. This was said to be a  compromise, a hybrid system between traditional banking and a peer-to-peer network.


How Ripple gateways work. (Source: Ripple.com)

In late 2012, OpenCoin opposed the usage of the name “Ripple Card” by Ripple Communications, a telecom company that predated the launch of the Ripple payment network. This may illustrate the start of a change in culture of the company, with a willingness to use the law to protect the company, and a change in strategy to focus more on the Ripple brand.


Ripple Communications is an unrelated telecom company based in Nevada that held the Ripple.com domain and used the Ripple name before the Ripple payment network came into being. (Source: Internet Archive)

In October 2012, Jesse Powell, the founder and CEO of the Kraken exchange (which launched in 2011) and close friend of McCaleb, participated in Ripple’s first seed round with an investment believed to total around $200,000. Roger Ver is also said to have been an early investor in Ripple, apparently investing “before even the creators knew what it was going to be”.

XRP token launch: January 2013

Ripple released its XRP coin in January 2013. Like Bitcoin, XRP is based on a public chain of cryptographic signatures, and therefore did not require the initial web of trust or gateway design. XRP could be sent directly from user to user, without the gateways or counterparty risk, which was the method used for all currencies on Ripple, including USD. Ripple perhaps intended XRP to be used in conjunction with the web of trust structure for USD payments — for example, to pay transaction fees. The company set the supply of XRP at a high level of 100 billion, with some claiming this would help Ripple prevent sharp price appreciation. Critics argued that the XRP token may not have been a necessary component of the network.

In April 2013, OpenCoin received $1.5 million in funding from Google Ventures, Andreessen Horowitz, IDG Capital Partners, FF Angel, Lightspeed Venture Partners, the Bitcoin Opportunity Fund, and Vast Ventures. This was the first in many rounds of venture funding and it included some of the most respected venture-capital companies in the world.

McCaleb left the project sometime between June 2013 and May 2014. Although his departure appears to have only been widely discussed within the Ripple community starting in May 2014, later statements from the company indicates he ended his involvement in June 2013 when Stefan Thomas took over as CTO. Thomas had created the We Use Coins website in March 2011 and the 2011 “What is Bitcoin?” YouTube video.

McCaleb appears to have disagreed with Larsen on strategy and then was seemingly forced out of the project, based on support Larsen received from the new venture-capital investors. After leaving Ripple, McCaleb went on to found Stellar in 2014, a project said to be based on some of the original principles behind Ripple.

Ripple Labs: September 2013 to October 2015

In September 2013, OpenCoin became Ripple Labs.

In February 2014, Ripple implemented the “balance freeze” feature, which it activated in August 2014. This allowed Ripple gateways to freeze or even confiscate coins from any user of its gateway, even without a valid signature for the transaction. The motivation of this was said to be to enable gateways to comply with regulatory requirements, for example, a court order demanding the confiscation of funds. The default setting for a gateway was to have the freeze feature enabled, but it was possible for a gateway to disable this option by using a “NoFreeze” flag, such that tokens a gateway owed could not be frozen or confiscated using this feature. The largest gateway at the time, Bitstamp, did not opt out of the freeze feature.

In May 2015, regulatory authorities in the United States fined Ripple Labs $700,000 for violating the Bank Secrecy Act by selling XRP without obtaining the required authorisation. Ripple additionally agreed to remedial measures, the most onerous of which are summarised below:

  • Ripple Labs must register with FinCEN.
  • If Ripple gives away any more XRP, those recipients must register their account information and provide identification details to Ripple.
  • Ripple must comply with AML regulations and appoint a compliance officer.
  • Ripple must be subject to an external audit.
  • Ripple must provide data or tools to the regulators that allows them to analyse Ripple transactions and the flow of funds.

Ripple: October 2015 to present

In October 2015, the company simplified its name to Ripple.


The current Ripple logo. (Source: Ripple.com)

In September 2016, Ripple raised $55 million in funding in a round lead by Japan’s leading online retail stock-brokering company, SBI Holdings (8473 JP). SBI acquired a 10.5% stake in Ripple. As we mentioned in our “Public companies with exposure to the crypto space” piece, this is part of a wide range of SBI investments into crypto. SBI and Ripple have set up a joint venture, SBI Ripple Asia, which is 60% owned by SBI and 40% owned by Ripple. The company is hoping to provide a settlement platform using Ripple’s “distributed financial technology”.

In September 2017, R3, another blockchain company, sued Ripple. R3 argued that Ripple agreed in September 2016 to give it the option to buy 5 billion XRP at an exercise price of $0.0085 before September 2019. At the peak, the intrinsic value of this call option was worth around $16.5 billion. R3 alleges that in June 2017, Ripple terminated the contract, despite having no right to do so. Ripple then filed a counter case, alleging that R3 did not honour its side of the original 2016 agreement by failing to introduce Ripple to a large number of banking clients or to promote XRP for usage in these banking systems. As of February 2018, the case is unresolved.

Ripple supply and company reserves

When Ripple was founded, it created 100 billion XRP tokens of which 80 billion tokens were allocated to the company and 20 billion were given to the three founders. Here is an approximate breakdown of the distribution of those tokens:

  • The Ripple company received 80 billion XRP.
  • Chris Larsen received 9.5 billion.
    • In 2014, Larsen committed to put 7 billion XRP of this 9.0 billion into a charitable foundation.
  • Jed McCaleb received 9.5 billion. Upon leaving Ripple:
    • McCaleb retained 6.0 billion (subject to lock up agreement).
    • McCaleb’s children received 2.0 billion (subject to lock up agreement).
    • 1.5 billion was given to charity and other family members of McCaleb (not subject to lock up agreement).
  • Arthur Britto received 1.0 billion (subject to lock up agreement).

When McCaleb left Ripple, there were concerns he was, could or would dump his XRP into the market and crash the price. McCaleb and Ripple constructed the following agreement to prevent this by restricting the sale of XRP. The agreement was revised in 2016 after Ripple accused McCaleb of violating the initial terms.

2014 agreement
  • McCaleb’s sales are limited to $10,000 per week during the first year.
  • Sales are limited to $20,000 per week during the second, third, and fourth years.
  • Sales are limited to 750 million XRP per year for the fifth and sixth years.
  • Sales are limited to 1 billion XRP per year for the seventh year.
  • Sales are limited to 2 billion XRP per year after the seventh year.

(Source: http://archive.is/cuEoz)

As for the 80 billion XRP held by the Ripple company, the plan was to sell or give away this balance, use the funds to fund company operations, and to use it to seed global money-transfer gateways. As the Ripple wiki says:

XRP cannot be debased. When the Ripple network was created, 100 billion XRP was created. The founders gave 80 billion XRP to the Ripple Labs. Ripple Labs will develop the Ripple software, promote the Ripple payment system, give away XRP, and sell XRP.

From December 2014 to July 2015, the company disclosed on its website the amount of XRP it held, the amount in circulation, and indirectly (by mentioning a reserve) the amount spent on company operations. The company did not distinguish between what it sold and what it gave away for free. The disclosure for 30 June 2015 is shown below.


(Source: Ripple.com)

Some time after July 2015 the disclosure was modified, with the reserve balance no longer available. Since at least late 2017 Ripple disclosed three figures, the “XRP held by Ripple”, “XRP distributed” and “XRP to be placed in escrow”. As at 31 January 2018, the balances are as follows:

  • 7.0 billion XRP held by Ripple
  • 39.0 billion XRP distributed
  • 55.0 billion XRP placed in escrow

We have been unable to link or reconcile the old Ripple reserve figure with the new XRP held by Ripple figure, therefore we are unsure how much the company has spent on its own operations across the entire period. However, we have analysed the information disclosed in the old way prior to July 2015, 12 data points in total, in addition to forum posts from the company’s current chief cryptographer David Schwartz (regarded as one of the main architects of Ripple’s technology, who goes by the name JoelKatz online and is said to have had 1 billion XRP). The following charts present our findings related to the distribution or spend of XRP.


XRP holdings from 2013 to 2015 – billion. (Source: BitMEX Research, Ripple.com)


XRP distribution (sales to partners plus XRP given away) and XRP spent on company operations – billions. The crosses represent points where information was available. We are not aware of why the amount spent on company operations appears to decline towards the end of 2015. (Sources: Ripple.com, https://forum.ripple.com/viewtopic.php?f=1&t=3645, https://forum.ripple.com/viewtopic.php?f=1&t=3590)


XRP in circulation – billions. (Source: Ripple.com, https://forum.ripple.com/viewtopic.php?f=1&t=3645, https://forum.ripple.com/viewtopic.php?f=1&t=3590, Coinmarketcap/new Ripple disclosure)

The data shows that Ripple sold or distributed 12.5 billion XRP from January 2013 to July 2015. We have been unable to determine how many XRP were sold, at what price, or how many were given away. The company spent at least 4 billion XRP on company operations between March 2014 and July 2015 but there are no details of what this was spent on, as far as we can tell.

Dispute between company founders

As we alluded above, McCaleb did not part with the company on the best of terms. In May 2014, early Ripple investor Jesse Powell described the situation:

Since Jed’s departure, the management of the company has taken a different direction. Sadly, the vision Jed and I had for the project in the early days has been lost. I’m no longer confident in the management nor the company’s ability to recover from the founders’ perplexing allocation to themselves of 20% of the XRP, which I had hoped until recently would be returned. Prior to Jed’s departure from Ripple, I had asked the founders to return their XRP to the company. Jed agreed but Chris [Larsen] declined — leaving a stalemate. This afternoon, I revisited the allocation discussion with the pair and again, where Jed was open, Chris was hostile.

Ripple responded to Powell with a claim that he was spreading false and defamatory information in violation of his obligations as a Ripple board member. The letter states:

In fact, as Chris has stated previously in discussions with you and Jed, he has been and remains willing to return most of his founders’ XRP to Ripple Labs.

Powell retorted that Larsen would return only a portion of his XRP to the company, and rather than giving it back, this would be a loan. Powell ends the letter by explaining how he sees the situation with respect to the 20 billion XRP granted to the founders and the formation of Ripple:

Jed and I got started with Ripple in September of 2011. I believe Chris joined sometime around August of 2012. Prior to Chris joining, the company had two investors. I’m not sure when Jed and Chris allocated themselves the XRP but they say it was before incorporation, which occurred in September of 2012. In my view, the two stole company assets when they took the XRP without approval of the early investors, and without sharing the allocation amongst the other shareholders. Whatever coin they allocated themselves prior to incorporation of Opencoin, I believe was abandoned. There had been several ledger resets between Sep 2012 and Dec 2012, and a new version of Ripple emerged, built by Opencoin, clearly with company resources. If Jed and Chris have continued to run the old software to preserve their Betacoin, I have no problem. Unfortunately, Jed and Chris again allocated themselves XRP in December of 2012. That XRP unquestionably was not gifted by Jed and Chris to the company, it did not exist prior to the company’s existence, and it was generated with company resources. That XRP has always belonged to the company and it was taken from the company by Jed and Chris. I’m asking them to return what they’ve stolen.

Powell continued to comment on the situation on the Ripple forum:

The board and investors have known about it for a long time. I’d been nudging them to return the XRP since I found out about it. Jed was always willing but Chris wasn’t, and Jed kept his share in case leverage was ever needed to more aggressively persuade Chris to return his portion. It wasn’t a regular topic of discussion and was just something I just imagined would work itself out when Chris got a grasp on the damage it was doing to Ripple’s image and adoption. If my goal had been to get my fair share, I probably would have been more proactive about it but I’d just assumed it would eventually be entirely returned to the company. I could have agreed to a small amount of XRP being paid out in lieu of cash compensation or instead of equity, but otherwise, we all should have bought our XRP at the market rate, like everyone else.

The company, through marketing VP Monica Long, then responded to the Powell’s continued public pressure with the following commitment:

Further, co-founder and CEO Chris Larsen has authorized the creation of a foundation to distribute his donation of 7 billion XRP to the underbanked and financially underserved. This plan has previously been in development but is now being accelerated and finalized independent of a formal agreement amongst all the original founders. He believes this is both the right thing to do and the best way to remove further distractions in pursuit of the broader vision of the company. Details of the foundation, its independent directors, and the giveaway will be forthcoming.

The above response appeared to divert the pressure on Ripple and Larsen that was building inside the Ripple community. The foundation that was set up is Ripple Works. We have reviewed the charity’s US tax filings for the fiscal years ended April 2015 and April 2016, which show the following donations of XRP:

Date Donor Amount (XRP)
November 2014 Chris Larsen 200 million
April 2015 Chris Larsen 500 million
July 2015 Chris Larsen 500 million
November 2016 Ripple Inc 1,000 million

As of April 2016, two years after the commitment, Larsen appears to have given at least 1.2 billion XRP out of the promised 7 billion XRP total to the foundation. We have not been able to obtain the filling for the year ended April 2017, as it may not be available yet.

The dispute and the Bitstamp Ripple freeze incident

In 2015, Ripple took advantage of the Ripple freeze feature instituted in August 2014. The Bitstamp gateway froze funds belonging to a family member of Jed McCaleb. Some consider this ironic: Ripple originally stated that the freeze feature was implemented to enable gateways to comply with orders from law enforcement yet the first actual usage of the feature appears to have been an order to comply with an instruction from the Ripple company itself, against one of the founders.

What appears to have happened is a family member of McCaleb sold 96 million XRP (perhaps part of the 2 billion XRP given to other family members and not part of the lock-up agreement) back to Ripple for around $1 million. After Ripple acquired the XRP for USD, Ripple appears to have asked Bitstamp to use the Ripple freeze feature to confiscate the $1 million Ripple had just used to buy the tokens. In 2015, Bitstamp took both Ripple and McCaleb to court, to determine the best course of action.

Court documents allege/reveal the following:

  • McCaleb had 5.5 billion XRP.
  • McCaleb’s two children held 2 billion XRP.
  • Another 1.5 billion XRP were held by charitable organizations and other family members.
  • In March 2015, Jacob Stephenson, a relative of McCaleb, offered to sell 96 million XRP to Ripple.
  • Ripple agreed to pay nearly $1 million to buy the 96 million XRP from Stephenson in a complicated transaction that “manipulated the market” to “improperly inflate the price per XRP of the transaction and mislead other purchasers”. As part of this, Ripple paid more than the cost and asked Stephenson to return an excess amount of $75,000.
  • Bitstamp’s chief legal officer was also an advisor to Ripple and as such there was a conflict of interest.

The dispute between McCaleb and Ripple continued until a final resolution in February 2016, when the company, implying that McCaleb had violated the 2014 XRP lock-up agreement, stated that a final settlement had been reached:

Jed exited Ripple back when it was OpenCoin in June 2013. He has played no role in the strategy or operations of Ripple since then. He has, however, held significant stakes of XRP and company shares. In August 2014, we shared the terms of a lock-up agreement that dictated timetables and limits within which Jed could sell XRP. The purpose of the agreement was to ensure distribution of his XRP in a way that would be constructive for the Ripple ecosystem. Since April 2015, Jed has been party to ongoing legal action related to alleged violation of the 2014 agreement.

McCaleb responded to this with his side of the story, indicating that he was also happy with the final agreement.

This week also sees the end of a longstanding issue. Stellar and I have finally reached a settlement with Ripple in the ongoing dispute between the parties. The settlement shows that Ripple’s claims were entirely baseless. Ripple has conceded in exchange for Stellar and I agreeing to settle the litigation.

Under the final agreement, McCaleb’s family member’s $1 million were unfrozen, Ripple agreed to pay all legal fees, and 2 billion XRP were freed for donation to charity. McCaleb would be free to sell his remaining XRP, perhaps over 5 billion XRP, consistent with the terms in the table below.

2014 agreement 2016 revised agreement
  • McCaleb’s sales are limited to $10,000 per week during the first year.
  • Sales are limited to $20,000 per week during the second, third, and fourth years.
  • Sales are limited to 750 million XRP per year for the fifth and sixth years.
  • Sales are limited to 1 billion XRP per year for the seventh year.
  • Sales are limited to 2 billion XRP per year after the seventh year.
  • McCaleb must donate 2 billion XRP to charity
  • McCaleb must retain title ownership of 5.3 billion XRP; however, Ripple will control the funds.
  • McCaleb and the charity will be able to collectively sell the following percentage of the average daily volume:
    • 0.5% in the first year,
    • 0.75% in years two and three,
    • 1.0% for the fourth year, and
    • 1.5% thereafter.

(Source: http://archive.is/cuEoz)

The Ripple consensus process

The consensus system

The Ripple technology appears to have gone through several iterations, but a core part of the marketing of Ripple is the consensus process. In 2014, Ripple used the image below to illustrate the consensus system, which seems to be an iterative process with servers making proposals and nodes only accepting these proposals if certain quorum conditions are met. An 80% threshold of the servers is considered a key level and once this threshold is crossed, a node regards the proposal as final. The image depicts some complexity in the process and the BitMEX Research team is unable to understand the detailed inner workings of the system or how it has any of the convergent properties necessary for consensus systems.


(Source: Ripple wiki)

In January 2018, the BitMEX Research team installed and ran a copy of Rippled for the purpose of this report. The node operated by downloading a list of five public keys from the server v1.ripple.com, as the screenshot below shows. All five keys are assigned to Ripple.com. The software indicates that four of the five keys are required to support a proposal in order for it to be accepted. Since the keys were all downloaded from the Ripple.com server, Ripple is essentially in complete control of moving the ledger forward, so one could say that the system is centralised. Indeed, our node indicates that the keys expire on 1 February 2018 (just a few days after the screenshot), implying the software will need to visit Ripple.com’s server again to download a new set of keys.


A screenshot of Rippled in operation. (Source: BitMEX Research)

Of course, there is nothing wrong with centralised systems; the overwhelming majority of electronic systems are centralised. Centralisation makes systems easier to construct, more efficient, faster, cheaper to run, more effective at stopping double spends and easier to integrate into other systems. However, some Ripple marketing, like the image below, contends that the Ripple system is distributed, which some may consider misleading.


(Source: Ripple.com)

In addition to the potentially misleading marketing, the construction involving the quorum process and 80% threshold may not be necessary and merely adds to the obfuscation, in our view. Defenders of Ripple could argue that the list of five public keys is customizable, as one could manually edit the configuration file and type in whatever keys one wants. Indeed, there is a list of such validators on the Ripple website. However, there is no evidence that many users of Ripple manually change this configuration file.

Even if users were to modify the configuration file, this may not significantly help. In this circumstance, there is no particular reason to assume that the system would converge on one ledger. For example, one user could connect to five validators and another user could connect to five different validators, with each node meeting the 80% thresholds, but for two conflicting ledgers. The 80% quorum threshold from a group of servers has no convergent or consensus properties, as far as we can tell. Therefore, we consider this consensus process as potentially unnecessary.

Validation of the ledger

Although the consensus process is centralised, one could argue that in Ripple user nodes can still validate transaction data from all participants. This model can be said to provide some assurance or utility, despite its computational inefficiency. Although moving the ledger forward is a centralised process, if the Ripple servers process an invalid transaction, user nodes may reject those blocks and the entire network would then be stuck. This threat could keep the Ripple server honest. However, this threat may not be all that different from the existing user pressure and legal structures which keep traditional banks honest.

Apparently, Ripple is missing 32,570 blocks from the start of the ledger and nodes are not able to obtain this data. This means that one may be unable to audit the whole chain and the full path of Ripple’s original 100 billion XRP since launch. This could be of concern to some, especially given Powell’s comments, which indicate that there may have been resets of the ledger in the early period. David Schwartz explained the significance of the missing blocks:

It doesn’t mean anything for the average Ripple user. In January of 2013, a bug in the Ripple server caused ledger headers to be lost. All data from all running Ripple servers was collected, but it was insufficient to construct the ledgers. The raw transactions still survive, mixed with other transactions and with no information about which transaction went in which ledger. Without the ledger headers, there’s no easy way to reconstruct the ledgers. You need to know the hash of ledger N-1 to build ledger N, which complicates things.

Conclusion

Much of this report has focused on disputes, primarily related to control over XRP, including accusations of theft. Perhaps such disputes are not particularly unique, especially given the rapid, unexpected growth in the value of the ecosystem. In fact, this story of the disputes might not be too dissimilar from that of some of the large tech giants mentioned in the introduction to this piece.

More significant than the disputes is the fact that the Ripple system appears for all practical purposes to be centralised and is therefore perhaps devoid of any interesting technical characteristics, such as censorship resistance, which coins like Bitcoin may have — although this does not mean that Ripple or XRP is doomed to failure. The company has significant financial capital and has proven somewhat effective at marketing and forming business partnerships, and perhaps this could mean the company succeeds at building adoption of the XRP token either among businesses or consumers. If so, the points that Bitcoin critics often raise may be even more pertinent and relevant in the case of XRP. These points include:

  • The lack of inflation is a naive economic policy.
  • The price of the token is too volatile and speculative.
  • Regulators will shut the system down if it becomes popular.
  • Perhaps most importantly, why not use the US dollar? Banks will build competing digital systems based on traditional currencies (if they don’t exist already).

The real mystery about Ripple is that, given the large market value of the system, why are all the Bitcoin critics so silent? Perhaps the answer to this question is just as applicable to some of Bitcoin’s proponents as it is to its critics. Most people seem to judge things based on what they perceive as the culture and character of those involved, rather than on the technical fundamentals.

Disclaimer

Whilst many claims made in this note are cited, we do not guarantee accuracy. We welcome corrections.

系统开发概要: 2018 年 2 月 2 日

在今天北京时间 21:00 , BitMEX 平台的交易量和实时注册量都创下了记录。此流量导致我们云伺服器上的代理网络流量堵塞,导致数据被迫进行备份。这些数据流太大最终导致一连串的网站用户请求新的数据映像,这么大的流量最后令网站一度瘫痪。

我们通过暂时停止交易,重置了受影响的平台服务及交易功能。之后几个小时的表现仍然不佳,但是我们成功解决了导致网速慢的两个主要系统之一。在撰写本文时,我们的读数显示网络延迟远远低于 24 小时平均值。

第二个系统将很快迁移,并将缓解这个问题。即便作出上述容量扩充,我们仍然面临引擎层面速度缓慢的情况,导致许多用户收到吓人的“过载”信息。我们了解客户正面临着这个问题,我们的团队也在积极解决该问题。解决方案涉及重新构建 BitMEX 操作系统,因此我们正在进行大量的规划和测试。一旦该项工作完成,我们会告知您。

其他消息方面,前端界面的一些更新也已经推出,包括一个新的弹出聊天框。由于升级关系,某些用户聊天框可能会卡在高速缓存。如果您的界面显示上述情况,请全屏显示图表,然后关闭全屏窗口。如果仍不起作用,请清除您的浏览器缓存。

 

NEO $100K Giveaway

BitMEX is happy to announce a new $100,000 giveaway for NEO (NEOG18) contracts!  

Start: Wednesday, 7 February 2018 at 00:00 UTC
End: Saturday, 17 February 2018 at 00:00 UTC

Prizes:

1 Grand Prize of 50,000 USD: The trader who continuously quotes the largest two-sided volume within a 0.5% spread gets the grand prize.*

1 Second Prize of 25,000 USD: The trader who continuously quotes the second largest two-sided volume within a 0.5% spread gets the second prize.*

1 Third Prize of 20,000 USD: The trader who has the largest profit (in XBT) from trading the NEO (NEOG18) contract gets the third prize.

1 Lucky Prize of 5,000 USD: Any trader who trades at least one NEO (NEOG18) contract automatically enters a random draw to win this prize.

*BitMEX will take snapshots of the orderbook at frequent intervals throughout the competition. A trader will add to their quoted volume in each snapshot by taking the minimum of their quoted bids and quoted asks within 0.25% either side of the midpoint. BitMEX will then sum that volume in each snapshot, and the trader with the largest cumulative volume at the end of the competition will win.

It’s simple to participate:

Cheers,
The BitMEX Team

Terms & Conditions:

1. BitMEX reserves the right to cancel or amend the giveaway or giveaway rules at our sole discretion.
2. Users who engage in market manipulation will be excluded from the contest. This determination will be made at the sole discretion of BitMEX.
3. Profit is defined as realized profit (in XBT terms) of all trades where the trade was opened and closed during the contest period window.
4. No user can win more than one prize.
5. Winners will be notified via email on 22 February 2018.
6. All awards are paid out in Bitcoin at the prevailing price of the .BXBT index at 17 February 2018 at 00:00 UTC.

Stellar Giveaway winners announcement

Thanks to all of the participants for helping to make the giveaway a success, and congratulations to all the winners! Please see the email you received for prize details.

A total of 1,993 participants entered the giveaway with a total of 4,403 tickets earned.

All 15 lucky winners were selected randomly from the 4,403 tickets. Any trader, big or small, can win a lucky draw, so make sure your name is in the hat for our upcoming giveaways.

To see the giveaway details, click here.

*Trader has agreed to show his/her real username in the winner announcement.

Wishing you a prosperous 2018!

Cheers!
The BitMEX Team

 

 

 

The art of making softforks: Protection by policy rule

Abstract: In this article, following on from our piece on the history of consensus forks, guest writer Dr. Johnson Lau explains the distinction between policy rules and consensus forks. He explains why it may be safer to introduce new softforks when the proposed rule is already covered by policy rules (non-standard behaviour), as this may mitigate or reduce some of the risks normally associated with changing the consensus rules.

(Source: gryb25)

Softforks are the primary way to fix and introduce new Bitcoin consensus rules. The following series of articles will describe how Bitcoin softforks are engineered.

Consensus rules and softforks

Consensus rules determine whether a transaction or a block is valid or not. Every user and miner on the Bitcoin network is expected to adhere to the same set of consensus rules, so they will all agree to a single ledger.

A softfork is an event when the majority of users and/or miners decide to adopt a stricter set of consensus rules, which makes some previously valid transactions/blocks invalid, but not the opposite. If the majority enforces the new rule set, any violating fork would (statistically) never catch up to the stricter fork in terms of total proof of work. The minority with the old rules set will always follow the longer and stricter fork, so everyone on the network would still agree to a single ledger.

Policy rules and consensus rules

While consensus rules are the only criteria for determining transaction validity, relaying or mining nodes may prefer some kinds of transactions over others. For example:

  • As spam control, transactions with very low fees or “sand outputs” (outputs with very low value) are rejected.
  • Some miners refused to include “on-chain casino” transactions, considering them spammy.
  • Transactions with an unknown version are rejected (currently only version 1 and 2 are “known”).
  • Transactions with exotic scripts (i.e., not P2PKH, P2SH, v0 segwit, or a few other cases) and unknown NOPx codes (currently only OP_NOP2 and OP_NOP3 are known) are rejected.
  • “Replace by fee” and “child pay for parent” are also policy rules, as they determine which transactions are preferred by miners.

By definition, policy rules MUST be at least as strict as consensus rules. Obviously, no miners would like to include invalid transactions in a block (which will lead to a loss of mining reward) or to relay them (which will get them banned by peers).

While policy rules could be stricter than consensus rules, it is important to note that policy rules do not determine the validity of transactions. Once a transaction is included in a valid block, all network nodes will accept it even if it violates some policy rules.

It is also important to note that policy rules are local, while consensus rules are universal. That means different network nodes might have different policy rules but they will still agree to the same blockchain ledger as long as they are running the same consensus rules.

Transactions that violate a policy rule are sometimes called “non-standard transactions”, distinguishing them from “invalid transactions”.

Policy rules and softforks

Ideally, all miners should have upgraded to the new, stricter rule sets on or before the activation of a softfork. Financially, they have a strong incentive to do this, as mining an invalid block (in terms of the new rules) would lead to significant monetary loss. However, in a decentralized system like Bitcoin, this is not guaranteed.

Although miners are expected to pay attention to any proposed rule changes and take timely action, miners who build invalid blockchain might lead to market disruption and monetary loss for ordinary users. Therefore, any well-planned softforks should bear this in mind and minimize the risks.

The trick is to make a softfork only if it is covered by existing, widely adopted policy rules. Miners with the policy rules who are unaware of the new consensus rules would refuse to include such transactions by default, so they would never include transactions that are invalid in terms of the new consensus rules. Some cases in Bitcoin history illustrate this.

A worker is adding a “Road Closed” sign to a route that is not being used due to an obstruction that existed before the sign was placed. The new traffic rules only prevent behaviour that was already “non-standard” and disruption is therefore minimal.

Case Study Description
BIP65: Check lock-time verify OP_NOP1 to OP_NOP10 originally had no meaning in the Bitcoin script language. While they are counted as one operation (there is a limitation of 201 operations in a script), practically, they are skipped during transaction validation. However, a policy rule has been included in Bitcoin Core since version 0.10 to reject OP_NOPx by default. BIP65 is a softfork introduced in Bitcoin Core 0.12 to redefine OP_NOP2 as OP_CHECKLOCKTIMEVERIFY (OP_CLTV). OP_CLTV checks if the top stack value is greater than the transaction’s nLockTime field (along with a few more conditions). If any of the conditions are matched, the transaction is considered as invalid. Otherwise, OP_CLTV is skipped like OP_NOP2.

New nodes would always enforce the new consensus rules after softfork activation. Yet even before the softfork was activated, the original OP_NOP2 policy rule was replaced by the OP_CLTV rules (which is okay, since OP_CLTV rules are stricter than the original OP_NOP2 consensus rules).

Legacy mining nodes would not perform the nLockTime check. However, as long as they were running version 0.10 or above, the default OP_NOP2 policy rule would prevent them from including ANY transactions with OP_CLTV, valid or not. As a result, legacy mining nodes of 0.10 or above would never actively produce an invalid block with respect to the new OP_CLTV consensus rules.

BIP68: Relative lock-time using sequence numbers nSequence is a field in Bitcoin transactions, which was essentially unused. The idea of BIP68 was to use the nSequence field for the purpose of relative lock-time, which is a very important building block of advanced transactions such as payment channels and the Lightning NetworkHowever, the nSequence field has been ignored since the very first version of Bitcoin, and miners would accept any transaction with any nSequence value. There was no policy rule governing nSequence value, therefore a safe softfork could not be done as simply as OP_CLTV.

The trick was to use the transaction-version field (nVersion). Since version 0.7, non-version-1 transactions are rejected by a policy rule. To leverage this, BIP68 requires that the new rules for nSequence are enforced ONLY if the transaction version is 2 or above (or below 0, to be precise). Therefore, legacy mining nodes would not produce any BIP68-violating block, since they won’t include any non-version-1 transactions by default.

An attacker could not “turn off” BIP68 by simply changing the transaction version, since the version is covered by signature. This is also the only instance in which the transaction version is associated with consensus rules.

BIP141: Segregated witness Segregated witness (segwit) is a softfork to fix transaction malleability by redefining a certain script pattern. In BIP141, the pattern is an output script (or P2SH redeemscript) which starts with a single OP_x (x = 0 to 16), followed by a canonical data push between 2 and 40 bytes. However, this is not what it was originally proposed. In the first draft, the witness-program pattern was a single push between 2 and 41 bytes.

A policy has been implemented since v0.6 to reject transactions that spend exotic scripts (i.e. not P2PKH, P2SH, and a few more types). The first draft of the witness program was indeed non-standard in this regards.

The problem is with the witness program when wrapped in P2SH. Before v0.10, the policy rules would also reject any exotic P2SH scripts. This rule was greatly relaxed in v0.10, and the original witness-program design was not covered.

A few alternative proposals were considered:

  • A new transaction nVersion (like BIP68) does not work. If the new consensus rule is “segwit rules are enforced only if nVersion is larger than 2”, an attacker could steal all money stored in segwit outputs by changing the nVersion (since the nVersion is covered only by the segwit signature, which is not checked when nVersion is 2 or below).
  • An OP_NOPx might be used to label a witness program. However, this would make all witness programs 1 byte bigger, and also occupy the limited OP_NOPx space.

The final version made use of the so-called “clean stack” policy rule from BIP62. Although BIP62 is now withdrawn, its rules are still enforced as policy. “Clean stack” requires that script evaluation must end with one and only one stack item. The final witness-program design, however, leaves two item on the stack. This is valid by consensus but violates “clean stack” policy.

Failing example: BIP16 and pay-to-script hash (P2SH) BIP16 was the first planned softfork on Bitcoin. It was activated when 55% of hash power signalled readiness (compared with the 80% to 95% currently in use). Before P2SH was introduced, there was no policy rule for checking the form of spending output. As a result, a significant number of miners kept creating invalid blocks, occasionally long chains, months after softfork activation.
Failing example: Segregated witness on Litecoin Not long after the Bitcoin segwit implementation was finalized, Litecoin started to integrate the segwit code. However, while segwit was released in Bitcoin Core 0.13.1, the last Litecoin version at that time was 0.10.4, which did not include the “clean stack” rule. Litecoin developers tried to fix the problem by adding an extra consensus rule to segwit that required the block version to be at least 0x20000000, hoping that would force miners to upgrade. It turned out that all miners upgraded right before the activation (with the last large miner upgrading a few hours before), and no fork was created due to the lack of “clean stack” in the last release.

Should a large mining pool have failed to upgrade at the last minute, the extra-block version rule would have provided little or no protection. This will be discussed in a future article.

Policy protection is not a panacea

At this point, a reader might find that the policy-protection trick described above would only prevent un-upgraded miners from actively making the first invalid block after softfork activation. However, should such an invalid block be somehow created, un-upgraded miners would still accept it and extend such a blockchain if it had more proof of work. So this is a way to only reduce but not eliminate the chance of an accidental chain split at softfork activation. This issue is also particularly problematic if a significant number of miners are using different full-node implementations, which might not have the same policy rules.

Dr. Johnson Lau, Bitcoin Protocol Developer

CC BY-SA 4.0

BitMEX Stellar Giveaway leaderboard 25 January 2018

Check your user name here:
https://www.bitmex.com/app/leaderboard

Or follow these steps:

  1. Go to the BitMEX platform.
  2. Click on Contracts from top menu bar.
  3. Click on Leaderboard from left navigation bar.

As a reminder, 15 randomly selected Stellar contract traders will be rewarded one of the 15 prizes:

1 Grand Prize of 25,000 USD
1 Second Prize of 10,000 USD
13 Third Prizes of 5,000 USD

Good luck to all participants!

Cheers,
The BitMEX Team

BitMEX Stellar Giveaway leaderboard 24 January 2018

Check your user name here:
https://www.bitmex.com/app/leaderboard

Or follow these steps:

  1. Go to the BitMEX platform.
  2. Click on Contracts from top menu bar.
  3. Click on Leaderboard from left navigation bar.

As a reminder, 15 randomly selected Stellar contract traders will be rewarded one of the 15 prizes:

1 Grand Prize of 25,000 USD
1 Second Prize of 10,000 USD
13 Third Prizes of 5,000 USD

Good luck to all participants!

Cheers,
The BitMEX Team

The Lightning Network

Abstract: In this piece, we explain the motivation behind the creation of the Lightning Network and why its scaling characteristics are superior to what we have today, potentially resulting in a transformational improvement. We describe some of the basic technical building blocks that make Lightning possible. We then examine some of its limitations, including the downsides of inferior security compared to transacting on-chain and why this makes Lightning potentially unsuitable for larger-value payments.

(Source: flickr.com)

The motivation behind the Lightning Network

Blockchain-based payment systems typically work in a “broadcast to everyone” mode, in that when one makes a payment, one needs to broadcast the transaction to all participants in the network.

Nodes in such a system must:

  • store the transaction indefinitely,
  • verify the transaction, and
  • relay the transaction.

Miners, meanwhile, are required to engage in an energy-intensive competitive process to determine if the transaction makes it into the ledger, just in case a conflicting transaction occurs.

There isn’t even special treatment for the recipient of the payment. For example, if one buys a coffee using Bitcoin, the transaction is broadcast to the entire Bitcoin network without prioritising propagation of the transaction data to the coffee shop or the coffee shop’s payment processor. Many consider this process to be inefficient. If the objective is to build a payment system used by millions of people across the globe, this method does not seem logical.

The old “broadcast to everyone” announcement method at sporting events, during Arsenal’s 3-3 draw at home to Sheffield Wednesday in May 2000. Prior to the widespread adoption of mobile phones, stadium announcers broadcast messages for individuals over the public-address system to all those in attendance. Mobile phones have made this process faster and more efficient, as messages can be sent directly to the intended recipient.

The Lightning Network represents an improvement in efficiency and uses a more logical payment-network structure. Instead of broadcasting a transaction to everyone, the transaction can be sent more directly to the payment recipient. Only when parties to the transaction are dishonest does one need to resort to the cumbersome process, which distributed censorship-resistant systems require to maintain consensus. In this way, one can achieve performance and efficiency almost equivalent to that of direct communication between the parties over the Internet, while retaining some of the security characteristics of Bitcoin’s blockchain.

However, building such a payment system, in which all parties can always revert to the blockchain and reclaim their funds if there is a problem, is complex and has some significant risks and limitations.

Lightning’s basic technical building blocks

Unidirectional micropayment channel. (Source: BitMEX Research)

The diagram above depicts the traditional way to set up a basic unidirectional payment channel. Although setting up the channel involves broadcasting a transaction to everyone, once the channel is set up, multiple payments from Bob to Alice can occur by simply sending data from Bob to Alice, avoiding a broadcast to the entire network. The payment process can be repeated again and again until the funds in the channel, in this case 1 BTC, have been exhausted.

In theory, the above channel is secure for the following reasons:

  • If Bob tries to renege on his payment, all Alice needs to do is sign and broadcast to the network transaction P1, which Bob signed when he initially made the payment. As long as this gets confirmed before the one-week locktime in transaction B, Alice safely receives her 0.1 BTC regardless of what Bob does.
  • If Alice refuses to sign anything in order to frustrate Bob, all Bob needs to do is wait one week for transaction B to become valid, and he is then able to move the money from the channel to himself by broadcasting transaction B, which Alice has already signed.

This process is more secure if transaction A cannot be malleated by a third party (the TXID changing), otherwise Bob could have created transaction B only for it to become invalid as transaction A changes, thereby enabling Alice to hold the funds hostage indefinitely.

According to an e-mail that Satoshi sent to Bitcoin developer Mike Hearn, this basic structure was Satoshi’s idea:

One use of nLockTime is high frequency trades between a set of parties. They can keep updating a tx by unanimous agreement.  The party giving money would be the first to sign the next version.  If one party stops agreeing to changes, then the last state will be recorded at nLockTime.  If desired, a default transaction can be prepared after each version so n-1 parties can push an unresponsive party out.  Intermediate transactions do not need to be broadcast.  Only the final outcome gets recorded by the network.  Just before nLockTime, the parties and a few witness nodes broadcast the highest sequence tx they saw.

(Source: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2013-April/002417.html)

How the Lightning Network actually works

This micropayment construction can be considered the core building block for the Lightning Network, which is essentially a network of these payment-channel-like constructions. Payments find a path along channels which are already directly connected to each other until they reach the final recipient.

The channel construction used in Lightning builds on this basic structure with more advanced and complex technologies. The above construction is unidirectional, while in order to be useful, payments need to be made in both directions. For example, one can think of making payment channels bidirectional by constructing two channels between Alice and Bob, each in the opposite direction. More precisely, Lightning uses Poon-Dryja channel construction. This has lower liquidity requirements than simply setting up a network of unidirectional payment channels in opposite directions, which would require twice the amount of funds to be locked up inside the channel. However, Poon-Dryja channel construction has significant weaknesses compared to the other approach. Poon-Dryja channels require each party to sign a new transaction every time the channel is updated (a payment is made) while a unidirectional channel only requires the sender to sign when the channel is updated.

The old locktime feature can be replaced with more advanced functions:

  • Check locktime verify (BIP65) can prove that the output cannot be spent until a certain date rather than ensuring a particular spend of the output is invalid until a certain date, which is what locktime does.
  • Relative locktime (BIP68) can replace a specific end date with a date relative to the corresponding output. This can allow payment channels to remain open for indefinite periods, with a closure transaction triggering a time window during which the other party has a finite period of time (e.g., two weeks) to broadcast their reclaim transaction and recover the funds.
  • Hashed timelock contracts (HTLC) can require the receiver of a payment to provide a string that hashes to a certain value by a certain date or returns the funds to the payer. This same hash can be used to trigger other payments in the channel network, enabling payments to be made across a chain of channels.

The resulting Lightning Network and its advantages

The Lightning Network should then, in theory, allow all participants in the network to make near instant and cheap transactions in all directions by finding a path among the nodes. This therefore avoids broadcasts to the Bitcoin network, as long as there are no problems, and results in a scalable network. The architecture even allows microtransactions and improves the privacy of payments.

Channels can stay open indefinitely due to the relative-locktime feature and there should be no counterparty risk; if anyone tries to steal funds through a hostile channel closure, the other participants to the transaction will have a significant time window in which to issue their own redemption transaction and get their money back.

Network functionality and user experience

A big unknown is how people and businesses will actually use the network, and commentators have different visions. Some see the Lightning Network as eventually being ubiquitous for small payments, with complexities handled in an automated way. Others more sceptical of Lightning typically envision the various components of the network requiring more of a manual construction when the system is used and a poor user experience plagued by unexpected channel closures and periods of Lightning Network downtime.

Sceptical view of Lightning Ambitious view of Lightning
Channel setup In order to set up a Lightning channel, a user must manually create a new expensive on-chain transaction. Setting up a Lightning channel will be a seamless process built into existing wallets and systems. When receiving a payment or purchasing Bitcoin, the funds need to go somewhere. Funds could immediately go into a Lightning channel as they are received and therefore setting up the channel requires no additional steps or costs.
Channel closure Once the payment is complete, one needs to close the channel, with a manually created, expensive on-chain transaction. There may be no need to close the channel and users can keep their wallet funds in channels indefinitely or for long periods of time.
Network routing Routing is likely to be a significant problem, since finding a short path between parties is a difficult problem to solve algorithmically. If no route is found, the user and merchant will have to engage in the cumbersome process of selecting an on-chain transaction by manually changing the payment process.

1. The existing P2P network already requires a network topology and the relaying of messages, with nodes typically having eight connections. The Lightning Network topology is simply an extension of that.

2. Routing is not a significant problem, since even in massive networks the average number of steps in a path between users is small.

3. Even if there is a problem with routing, a payment could simply be made on-chain without the user even noticing the difference.

4. A small number of large channel operators can prevent routing problems.

Centralisation of payment channels The network will centralise around a few large hubs as this is the most efficient model. This centralisation increases the risk of systemic channel failure, which is when a few large channels fail, resulting in a simultaneous mass exodus from payment channels and on-chain congestion, ensuring that some are unable to exit the channels before expiry.

Economic incentives act against centralisation; anyone can set up a node as there are low barriers of entry. In addition, there is an incentive to undercut other nodes by charging lower fees.

Even if the network does centralise around a few large hubs, the Lightning Network still provides a useful and interesting system. Bitcoin already has a few large entities such as Coinbase that take custody of a large amount of funds.

Under Lightning, the entities do not have custody of funds and merely act to relay data used for payments.

Liquidity Payment channels will have insufficient liquidity and therefore the scope of payments will be limited. Payments of any reasonable size can almost instantly drain the liquidity of an entire channel, such that Lightning payments will need to be suspended. Users will be incentivised to run Lightning nodes and provide liquidity in order to receive fees. The network will be used for small payments, far smaller in value than the maximum channel capacity, ensuring sufficient liquidity.
Requirement to be online when receiving a payment With an on-chain transaction, all a sender needs is a payment address to make a payment; the recipient does not need to be online. In contrast to this, as explained above, a recipient in Lightning will need to sign a reclaim transaction before receiving a payment. This significant limitation means that recipients are required to keep their private keys exposed in a hot wallet. This makes Lightning impractical in many scenarios, such as making high-value payments, at ATMs, at in store PoS systems, or paying those with limited Internet connectivity. Although a recipient is required to be online to receive a payment, this does not result in significantly different dynamics to most on-chain payments, since if the recipient is not online, they don’t know about or cannot verify the payment anyway. It is also not necessary that the user or device directly receiving the payment needs to store the private keys. For example, an in-store PoS terminal or a crypto ATM machine could receive the signed redemption transaction over the Internet from the firm’s HQ prior to receiving payments, communication that is necessary when making payments anyway.
Potential requirement to monitor the channel Lightning Network participants may be required to monitor payment channels and then take action by a certain deadline in order to safeguard their funds. For example, a hostile reclaim transaction could trigger the start of a period in which the other party must also issue a reclaim transaction to protect their funds, before a certain deadline. This is a significant burden on users. Channels do not need to be monitored at all times, as this depends on the window provided by the relative locktime. Channel-monitoring services (watchtowers) could mitigate this risk by monitoring channels on behalf of users: these services could either warn users in the event of a hostile reclaim transaction or could issue reclaim transactions themselves, if they were pre-signed and supplied beforehand by the users.

In reality, the truth may lie somewhere between these two visions, with the network potentially moving to the more ambitious vision over time. What this disagreement appears to come down to is that Lightning sceptics see it as a complex, incomplete, and impractical payment system based on the channel-construction system alone. Proponents see Lightning more as a scalable building block for a second layer on top of Bitcoin’s blockchain, which will eventually be supplemented by wallets, payment protocol systems and channel-servicing companies, resulting in a simple and seamless user experience. Ultimately, wallets may be able to communicate with each other and then automatically, dynamically decide which payment methodology is best, on-chain or the most practical method via Lightning, without the user even knowing or caring.

The increased security risks of Lightning

  • Requirement to be online when receiving a payment: As explained above, before receiving a payment, the recipient needs to sign a reclaim transaction so that the sender knows they can reclaim their funds in the event of hostile channel closure or a refusal to sign. Therefore, to receive money requires a hot wallet, meaning that private keys are potentially exposed if a security incident occurs.
  • Requirement to monitor the channel: Lightning Network participants or watchtowers may be required to actively monitor the payment channels. This could place a burden on users or watchtowers and potentially reduces the security of funds inside a channel relative to Bitcoin stored on-chain. There is a risk of missing a reclaim-transaction deadline, either due to a failure to appropriately monitor the channel or perhaps because of on-chain network congestion.
  • Miners could censor channel-closing transactions: 51% of the hashrate may have the ability to steal funds from Lightning users by censoring a channel-closure transaction, in which the miner is the other party. Although the potential consequences of this type of attack are already devastating without Lightning, the Lightning Network potentially offers hostile miners a slightly larger attack surface.

While each of these three factors alone may not be significant, the need to potentially expose one’s private keys to the Internet when receiving payments, the risk of a hostile channel closure, and the risk of miners censoring channel-redemption transactions combined result in significantly inferior security — although all these risks can be managed to some extent.

There is a risk that lazy or poorly informed users keep too much money in a channel and funds are lost or stolen due to one of these failure scenarios. There is also the risk that price volatility results in users keeping more funds in payment channels than they would otherwise have intended.

Conclusion

The Lightning Network does appear to potentially offer significant and transformational improvements with respect to scalability. As a result, transaction speeds and transaction fee rates should dramatically improve, without impacting the underlying security of the core protocol. Crucially, however, the inferior security properties of Lightning payments may make the Lightning Network unsuitable for larger payments (or, at least, it may be irresponsible to use it for larger payments). Speculation and investment flows, which require these larger payments, currently appear to be the major driving force in the cryptocurrency space, with the volume of retail payments being relatively small in comparison. Because of that, Lightning may not be as big a game changer as some imagine, at least in the medium term. While enthusiasts appear likely to adopt this technology quickly, widespread adoption may take considerable time.

BitMEX Stellar Giveaway leaderboard 23 January 2018

Check your user name here:
https://www.bitmex.com/app/leaderboard

Or follow these steps:

  1. Go to the BitMEX platform.
  2. Click on Contracts from top menu bar.
  3. Click on Leaderboard from left navigation bar.

As a reminder, 15 randomly selected Stellar contract traders will be rewarded one of the 15 prizes:

1 Grand Prize of 25,000 USD
1 Second Prize of 10,000 USD
13 Third Prizes of 5,000 USD

Good luck to all participants!

Cheers,
The BitMEX Team