What Is BIP 119 And Why Did It Fuel Such Heated Discussions In Bitcoin?

It’s been hard to disregard the treatment astir CheckTemplateVerify (CTV) implicit the past fewer weeks arsenic it has seemingly been generating a disagreement successful the Bitcoin assemblage with developers, users and companies taking sides connected whether the activation of the projected upgrade would beryllium a nett affirmative oregon antagonistic to the network.

Amid the discussion, however, galore misconceptions surfaced connected what CTV really is and what it tin and cannot do. Therefore, an easy-to-follow mentation is successful bid to wide up misconceptions earlier diving into the details of the caller debate.

What Is CTV? Clearing Up Misconceptions

CTV was archetypal projected successful May 2019 nether a antithetic name. At the time, the proposal, coined CheckOutputHashVerify, focused connected enabling congestion power connected Bitcoin — a method that lets aggregate payments beryllium sent and confirmed to galore users without burdening the blockchain until a aboriginal time. It besides enabled different usage cases, however, including vaults. In the pursuing month, the connection was refined aft feedback was received and it was renamed to SecureTheBag. Later that year, it was again improved and renamed to CTV.

CTV is simply a connection to amended Bitcoin done a brushed fork, a benignant of upgrade that ensures that nodes that take not to update tin inactive enactment successful the web arsenic agelong arsenic a bulk of hash powerfulness enforces the caller rules. It is specified successful Bitcoin Improvement Proposal (BIP) 119, wherever its author, Jeremy Rubin, lays retired its plan and reasoning arsenic good arsenic immoderate usage cases the connection could enable.

CTV allows a idiosyncratic to restrict wherever they tin walk immoderate of their ain bitcoin (beyond backstage cardinal ownership oregon timing rules specified arsenic successful the lawsuit of a timelock), a setup known arsenic a covenant. Although this seems contradictory and against Bitcoin’s ethos of sovereignty, determination are instances wherever restrictions connected wherever bitcoin tin beryllium spent tin beryllium desirable.

Who Could Restrict How You Spend Your Bitcoin With BIP 119?

A 3rd enactment would not beryllium capable to restrict however you walk your bitcoin if CTV gets added to the network. Rather, the projected brushed fork allows spending conditions to beryllium restricted only by the enactment receiving the bitcoin.

This really ties backmost to the mode Bitcoin fundamentally works: the enactment receiving bitcoin is the 1 to find the conditions for spending those funds adjacent – and not the sender.

The mode it works is the receiving enactment constructs an code that embeds immoderate accusation and sends that to the sending party. At the precise least, this accusation lays retired the conditions idiosyncratic needs to fulfill successful bid to walk that bitcoin. Since the receiver is the 1 to specify the accusation utilized to conception the receiving address, lone the receiver tin specify the spending conditions indispensable to walk that bitcoin aft it gets to that address. The process of satisfying those spending conditions is commonly known arsenic “unlocking” that bitcoin output.

This accusation successful the code could besides specify however galore signatures are indispensable to unlock the bitcoin funds successful that code (multisignature) oregon however agelong 1 needs to hold earlier being capable to unlock those funds (timelock).

Therefore, today, astir of the restrictions the receiving enactment tin specify subordinate to conditions for unlocking the bitcoin. But aft those conditions are satisfied and the bitcoin is unlocked, the idiosyncratic is escaped to walk it to immoderate code they privation successful astir immoderate transaction they tin deliberation of.

With CTV, the idiosyncratic constructing the code would beryllium capable to adhd much accusation indispensable to beryllium satisfied to walk that bitcoin — accusation that would fto the idiosyncratic restrict wherever the coins tin beryllium sent to aft the close signature is provided. In different words, the idiosyncratic tin programmatically specify successful beforehand what transactions volition beryllium capable to walk the bitcoin successful that address.

What Could BIP 119 Bring To Bitcoin?

CTV enables vaults, which could bounds withdrawals retired of acold retention to pre-specified addresses successful predetermined amounts. In practice, this could let a idiosyncratic to configure however overmuch BTC they privation disposable for removing retired of their semipermanent savings wrong a fixed clip framework and to which addresses.

For example, the idiosyncratic could find that nary much than 0.1 BTC tin travel retired of their vault and into their blistery wallet per week. This setup would bounds losses – done the transportation limits – successful lawsuit an attacker managed to get power implicit the user’s acold retention wallet backstage keys. Without a vault, having the backstage keys would let the attacker to expanse each of the user’s funds astatine once.

Beyond vaults, CTV has different absorbing applications arsenic well, including congestion control and outgo pools and astatine slightest two improvements to the Lightning Network. See a much extended database of usage cases successful this webpage.

Some BIP 119 Use Cases Can Already Be Achieved Today — With One Difference

All bundle has risks. That being said, 1 absorbing facet of CTV is that astir of the usage cases it enables tin already beryllium achieved today. However, close present they would necessitate users to beryllium online and coordinate signing and broadcasting transactions, arsenic good arsenic astatine times deleting backstage keys. This arguably makes them astir impractical, portion immoderate aspects, specified arsenic cardinal deletion with counterparties, present the constituent of trust.

CTV simply allows specified usage cases to beryllium completed programmatically, that is, without quality enactment aft the instauration of the declaration — an allegedly much trustless mode that is besides little prone for error.

Can BIP 119 Be Used To Implement Whitelists And Compromise Fungibility?

Some radical person articulated fears that, if activated, BIP 119 would facilitate governments and exchanges to create and enforce whitelists.

In the discourse of Bitcoin, a whitelist is simply a database of Bitcoin addresses that are approved for usage by immoderate authority. This authorization would lone let transactions to and from whitelisted addresses, banning each different addresses.

The fearfulness is that this could beryllium leveraged successful an authoritarian mode by governments worldwide done argumentation dictating that bitcoin could lone beryllium sent to addresses whitelisted by regulators.

It appears that immoderate judge CTV would beryllium capable to let governments oregon exchanges to restrict wherever the bitcoin they nonstop to users successful withdrawals could beryllium spent done whitelisting.

This fearfulness apt became fashionable aft salient Bitcoin pedagogue Andreas Antonopolous posted a video connected YouTube commenting connected CTV and covenants successful general, wherever helium discussed that covenants tin beryllium risky depending connected their design.

Antonopoulos said that recursive covenants, successful immoderate cases, could beryllium utilized to make blacklists and whitelists of Bitcoin addresses, perchance compromising Bitcoin’s fungibility arsenic immoderate BTC coins would beryllium antithetic than others fixed their spending abilities. But contempt the information that Antonopoulos did not accidental this would beryllium imaginable with CTV, galore radical assumed that helium was referring to CTV specifically — oregon simply bundling each “covenant” designs into 1 basket.

CTV does not let for recursive covenants oregon specified authoritarian whitelists. (Some Bitcoin developers really advocate that CTV is excessively simple successful its signifier and more wide covenant designs that screen a wider scope of usage cases would beryllium desirable instead.)

What Is All The Controversy About?

Perhaps the biggest portion of the contention surrounding CTV implicit the past mates of weeks has really been related to its activation method alternatively than its method specification, arsenic radical weighed successful connected whether the connection should determination guardant successful an attempted brushed fork upgrade to Bitcoin oregon not.

The uproar began aft Rubin posted to the bitcoin-dev mailing list connected April 19 outlining a suggested program for activating his connection connected the Bitcoin protocol. His email linked to an extended blog post which began with a conclusion: “Within a week from today, you’ll find bundle builds for a CTV Bitcoin Client.”

Rubin explained however helium attempted to stitchery feedback from antithetic members of the Bitcoin assemblage astir CTV during the Bitcoin 2022 conference, which gathered implicit 20,000 radical successful aboriginal April successful Miami.

Rubin said “a batch of people” told him that CTV could assistance them successful a tangible mode and were funny to cognize what the adjacent measurement was for the connection arsenic good arsenic what his plans were for getting it activated.

Additionally, arsenic summarized by Bitcoin Optech, Rubin elicited aggregate reasons successful the blog station for wherefore CTV could beryllium seen arsenic acceptable to activate, including consistency, popularity, viability and desirability. The developer argued that CTV has a unchangeable specification and implementation, a fig of well-known radical and organizations enactment the upgrade, determination seemingly is not a important objection that CTV violates desirable Bitcoin properties, and the upgrade would bring astir caller features that users allegedly want.

The developer planned connected releasing a Bitcoin lawsuit that would alteration miners to awesome whether they intended to enforce CTV rules oregon not. A Bitcoin lawsuit is simply a bundle exertion that interfaces idiosyncratic enactment with the Bitcoin network. A lawsuit tin afloat link to the peer-to-peer network, similar Bitcoin Core. While Bitcoin Core is the original, astir fashionable Bitcoin client, it is not the lone one.

The CTV lawsuit would bring codification that would marque it imaginable to activate the connection with Speedy Trial (ST), Taproot’s activation method from past twelvemonth that progressive miner signaling of readiness.

If 90% of the Bitcoin blocks successful immoderate of the galore 2,016-block (two-week) trouble periods signaled positively for CTV, the upgrade would beryllium “locked in” for activation successful November. Then, anyone moving Rubin’s Bitcoin lawsuit would beryllium capable to usage CTV and statesman enforcing its rules.

Under the archetypal plan, Rubin would merchandise the lawsuit bundle connected April 26. The archetypal signaling play would statesman connected May 5 and the signaling model would extremity connected August 12. This choky timeline made radical anxious astir the aboriginal of Bitcoin, particularly owed to the information that the upgrade would beryllium enactment distant done Speedy Trial by a lawsuit other than the network’s de facto notation client, Bitcoin Core.

As a result, a oversea of arguments ensued arsenic radical advocated for what they thought was the champion people of action.

Is BIP 119 Ready To Be Added To Bitcoin?

It is conscionable arsenic hard to find readiness arsenic it is to gauge statement — and some are apt intertwined arsenic it tin beryllium argued that statement is simply a operator for readiness. However, it isn’t wide however either 1 oregon the different are measured successful the Bitcoin ecosystem.

While BIP 119’s imminent activation is intelligibly not overwhelmingly supported, and hence not desired by everyone, the thought of covenants seemingly has wider enactment from the improvement community.

Most salient Bitcoin developers look to beryllium leaning toward encouraging a much extended probe successful the covenants taxable and the projected alternatives to enabling it connected the protocol.

Bitcoin developer Matt Corallo expressed successful the unofficial CTV Telegram radical chat that assorted usage cases enabled by covenants would astir apt beryllium “best served” with a operation of the antithetic proposals connected the table.

“But there’s precious small investigation of however these things would enactment together, however to physique them truthful that they enactment good together, however to physique a bully solution that has both,” helium said.

“Of people there’s nary ‘optimal solution for each use-cases.’ But determination is simply a satellite wherever we survey what we’re designing for and physique things that enactment good together,” helium added.

Corallo had posted connected the mailing list 1 time earlier his comments connected the Telegram group. His station warranted caution and highlighted that aggregate covenant-based designs person been proposed. In his opinion, the assemblage should strive to effort a brushed fork lone erstwhile it’s definite it provides the champion worth for a alteration — thing that would necessitate a much extended investigation and examination betwixt proposals.

“We don’t adhd things to Bitcoin conscionable to find retired whether we can,” helium wrote.

However, successful the aforesaid mode that it is unclear whether CTV is acceptable to beryllium activated, it is besides unclear what the adjacent steps should beryllium to either gauge that readiness oregon marque it ready. And reviewers haven’t laid retired specified steps.

Most of Rubin’s complaints stem from the deficiency of answers to his main question: What does CTV request to beryllium considered acceptable for activation into Bitcoin?

Such deficiency of directives from Bitcoin Core maintainers and chap Bitcoin developers was besides what drove him to effort the merchandise of his bundle lawsuit — truthful that users funny successful utilizing the features enabled by the brushed fork had the accidental to spot them live.

Moreover, this unclear process from connection to activation successful regards to Bitcoin brushed forks has brought to the fore a broader issue: How should we alteration Bitcoin?

How Should Changes To Bitcoin Be Made?

Taproot, the past large upgrade to the Bitcoin protocol, activated past twelvemonth aft the Speedy Trial process proved palmy successful gathering traction with the mining community. However, ST itself did not person peculiarly ample consensus and it is unclear if the assemblage wants to repetition it successful aboriginal brushed forks.

“ST [Speedy Trial] itself was reasonably controversial, but specifically what made it enactment for Taproot is Taproot had wide enactment and method consensus,” Blockstream CEO and aboriginal cypherpunk Adam Back said successful the unofficial CTV Telegram radical chat. “CTV has immoderate but IMO little wide enactment and does not [have] method consensus.”

Lightning Labs CTO Olaoluwa Osuntokun tweeted precocious past month comments that successful portion echo Back’s thoughts but astatine the aforesaid clip present a broader discussion. He said that Taproot enabled the assemblage to “kick the tin down the roadworthy and not code the captious question” of however changes should hap to Bitcoin.

“Some deliberation that [it] doesn’t request to beryllium spelled retired and ‘rough consensus’ (know it erstwhile you spot it) is enough, others deliberation we request a wide process/progression truthful we tin make much rigorous process astir it,” Osuntokun said successful a reply tweet.

“Reading betwixt the lines, immoderate deliberation a wide process gives a benignant of blueprint for aboriginal ‘attackers’ and the process is amended murky to ‘protect’ the system,” helium added. “Some deliberation without a process, statements similar ‘not technically ready’ can’t beryllium determined ‘objectively.’”

Besides the “technical consensus” statement made by Back, ordering is besides of importance. In the lawsuit of Taproot, the connection gathered overwhelming bargain successful from the assemblage earlier being handed disconnected to miner signaling with Speedy Trial. The other would hap with CTV nether the archetypal connection for activation, with Speedy Trial being utilized arsenic a means to stitchery oregon gauge statement alternatively of a means to fast-track a widely-supported upgrade to activation.

Casa co-founder and CTO Jameson Lopp disagrees.

“It seems to maine that if 1 proposes a speedy proceedings without method / ecosystem consensus, thing happens,” helium tweeted successful effect to Back, who was arguing that immoderate upgrade connection to Bitcoin should stitchery method and ecosystem statement earlier an attempted activation to the protocol.

“What is Bitcoin’s alteration process? It’s precise meta – nary of the conventions MUST beryllium followed. It is immoderate works,” Lopp argued successful a erstwhile tweet successful that treatment thread with Back.

The request for an upgrade connection to beryllium technically ready, oregon person method consensus, is simply a constituent Back has been trying to thrust location implicit the past fewer weeks arsenic the treatment astir CTV heated up. The cypherpunk has besides cited imaginable “drama” of what helium calls “non-consensus changes” — making parallels with the blocksize wars.

For Back, method statement arises from the radical analyzing and proposing covenant-enabling variants for Bitcoin. But that is arguably besides subjective, and arsenic highlighted by Osuntokun, fixed the “murky” upgrade process to Bitcoin, it is hard to specify what method statement is.

Ultimately, Nothing Happened

It is unclear why, specifically, Rubin’s blog station generated truthful overmuch treatment and fearfulness successful the community. However, determination are immoderate apt scenarios.

First, arsenic nontechnical users tend to trust connected the sentiment of salient developers and educators, seeing them not agreeing with each different connected a wide way guardant apt brought doubts astir the future, which ended up bleeding into the connection itself — casting doubts connected its merits and whether it was a bully thought aft all.

Second, determination appears to person been immoderate flimsy misunderstandings astir what Rubin intended to bash with his blog station and the merchandise of the software.

Some assumed helium would beryllium releasing a user-activated brushed fork (UASF) and got tense astir it, portion others got frustrated precisely due to the fact that helium wouldn’t bash that himself. Those successful favour of a UASF were besides tense partially owed to the previously-mentioned controversies with Speedy Trial — a miner-activated brushed fork (MASF). Rubin posted to the mailing list explaining immoderate of these nuances and what helium meant with the blog post.

It besides appears from the discussions successful the assemblage that galore did not announcement that Rubin jointly announced the merchandise of codification to resist the CTV activation successful his blog station — giving users some for and against the connection a accidental to dependable their sentiment successful the network.

All of these misunderstandings generated a batch of the play that Back spoke astir arsenic users were faced with fearfulness mongering that an update which method Bitcoiners couldn’t hold connected would beryllium “forced” onto the web by its proponents — perchance risking a concatenation split.

However, arsenic argued by Lopp, undertaking a Speedy Trial for a connection that doesn’t person overarching statement would apt person resulted successful nothing.

Despite the conversations and feedback, up to this point, beauteous overmuch thing has happened with the connection arsenic Rubin posted to the mailing database explaining that helium would not beryllium releasing immoderate codification arsenic antecedently intended.

Thanks to Aaron van Wirdum for accusation and feedback and to Jeremy Rubin for information.

For a much elaborate mentation connected CTV, spot this article. If you similar audio, spot this podcast episode connected CTV.