By Bitcoin Tydskrif - 3 maande gelede - Leestyd: 5 minute
Hoe CTV kan help skaal Bitcoin
OP_CHECKTEMPLATEVERIFY has once again become a focal point in the conversation about improvements to scale Bitcoin. This time around there are many more alternative designs for covenants being proposed, and actual concrete designs that make use of CTV as scaling solutions (Timeout Bome en Ark). The conversation has a much larger depth of concepts to take into consideration, both in terms of alternatives that could be adopted as well as concrete proposals that CTV could enable.
One narrative circulating from the camp of people against CTV is that “CTV doesn’t scale Bitcoin.” Let’s charitably interpret that to mean that CTV itself does not scale Bitcoin, things you can build with it do. Well, then that is not a coherent argument. Segregated Witness did not scale Bitcoin. CHECKLOCKTIMEVERIFY and CHECKSEQUENCEVERIFY did not scale Bitcoin. But the Lightning Network, which those three proposals enabled, do scale Bitcoin. They add a massive amount of overhead for transactional throughput to grow beyond the constraints of the blockchain self.
Lightning literally couldn’t exist without those base layer primitives. The problem with Lightning though, is it only scales the number of transactions that can be processed. It does not in any way help improve the scalability of ownership over UTXOs, or increase the number of users who can control one. Lightning is currently not capable of doing that with its current design and the current set of consensus primitives available in Bitcoin skrifte.
CTV kan dit verander.
UTXO's en virtuele UTXO's
Part of the problem of Lightning’s shortcoming regarding scalability of Bitcoin ownership is that in order to open a channel, or control a UTXO, you actually have to transact on the base layer. After that Lightning can facilitate a very large number of transactions off-chain, but a user must still transact on-chain to onboard themselves to Lightning. It massively increases the number of transactions Bitcoin can process, but it does nothing at all to increase the number of people who can own bitcoin.
This is another big problem CTV can help with. Burak coined the term “virtual UTXO” for his Ark proposal, but I think this terminology is a perfect general term useful far beyond the context of Ark. A virtual UTXO is one committed to being created in the future, through mechanisms like a pre-signed transaction, but that hasn’t actually been created on-chain yet. Bitcoin does not have the blockspace for everyone to create a single UTXO at the scale of the world population, but there is definitely potential for people to have their own independent virtual UTXO if the process of committing to those can be made scalable.
Scaling the creation of commitments to vUTXOs is the problem. Right now there is no way to create them except through the use of pre-signed transactions, and this introduces a bottleneck that must be addressed. The number of vUTXOs any real UTXO can commit to is bounded by the size of the multisig set signing these transactions. To trustlessly create vUTXOs, the owner of every vUTXO must be part of the multisig key that is signing the transactions that commit to creating them, otherwise they have no guarantee that conflicting transactions will not be generated that voids their ability to claim their vUTXO if necessary. The problem of coordinating the signing of this between every member of the set introduces practical considerations that will ultimately severely limit the size any pool of vUTXOs can grow to. The only other alternative is to have some trusted party or parties sign the transactions committing to everyone’s vUTXOs, and simply trusting them to not steal those funds from the rightful owners.
CTV bied 'n oplossing vir beide hierdie probleme. Deur in staat te wees om nie-interaktief te verbind tot 'n stel toekomstige transaksies op dieselfde manier wat vooraf ondertekende transaksies doen, maar sonder dat elke eienaar van die vUTXO's wat daardie transaksies skep vereis om ondertekening te koördineer, los dit die koördinasieprobleem op. Terselfdertyd, omdat niemand interaksie hoef te hê nie, kan 'n enkele persoon die rol neem om die CTV-uitset te finansier wat verbind is tot almal se vUTXO's wat in die ketting ontvou, en geen vertroue in daardie persoon nadat die befondsingstransaksie bevestig is nie. Sodra daardie regte UTXO in 'n blok bevestig is, het die persoon wat dit befonds het geen vermoë om die toekomstige transaksies waartoe hy verbind is, ongedaan te maak of te verdubbel nie.
Keep in mind that a vUTXO can be whatever you want it to be. It can be a Lightning channel, a multisig script for cold storage, etc. CTV does what the current form of Lightning does not, it scales actual ownership of Bitcoin, not just the number of transactions it can process.
Sny deur die kortpad
One of the other criticisms of CTV as “not scaling Bitcoin” is that by committing to future transactions you do not escape the need to put them on-chain eventually, and so therefore CTV doesn’t actually help improve scalability. I like to call this “the OP_IF fallacy.” i.e. once people start talking about CTV they forget OP_IF exists, and that scripts can actually have multiple spending conditions to choose from.
Die kragtigste dinge van Taproot is die vermoë om multisigs te konstrueer deur net twee publieke sleutels bymekaar te voeg en daarvoor te teken met 'n enkele totale handtekening, en om slegs selektief 'n enkele "IF"-tak van 'n skrif te openbaar wat verskeie maniere het om bestee te word . Gekombineer met CTV, bied dit 'n baie kragtige manier om van vUTXO-verpligtinge gebruik te maak. Eerder as om 'n ketting van transaksies met suiwer CTV te maak, kan hulle saamgestel word met die CTV-bestedingspad wat binne 'n penwortelboom begrawe is. Die einde van die ketting van transaksies is al die individuele vUTXO's wat elke deelnemer besit, gesluit tot daardie gebruiker se publieke sleutel alleen. Soos jy agteruit gaan na die wortel van die boom, kan elke stel sleutels wat onder enige nodus in die boom is, eenvoudig saamgevoeg word en gebruik word as die Schnorr multisig-sleutel waaronder die CTV-uitgawepad begrawe is.
Dit beteken dat op enige punt in die ketting van transaksies wat aan die ketting ontvou om die vUTXO's in werklike UTXO's te omskep waar jy elke deelnemer aan 'n intermediêre UTXO kan kry om met mekaar te koördineer, almal eenvoudig saam 'n transaksie kan onderteken wat hul munte beweeg waarheen hulle wil op 'n meer doeltreffende manier gaan as om bloot die voorafbepaalde transaksie te laat ontvou om hul vUTXO's in regte te verander. Dit laat klein subgroepe toe om te ontsnap deur die behoefte om die hele stel transaksies wat vooraf aan die ketting verbind is, te ontvou, sonder om enige vertroude partye bekend te stel om op te vertrou of die sekuriteit van elke gebruiker se aanspraak op hul eie vUTXO's te verswak.
These two simple realities offer a massive gain in scalability for Bitcoin without compromising on individual sovereignty or security in doing so, and all we need in order to realize them is CTV.
Bedankings: Ek wil graag almal bedank wat aan die Chicago Bitdevs deelneem dat hulle my gehelp het om hierdie waarnemings op 'n bondige manier deur middel van bespreking te formuleer.
Oorspronklike bron: Bitcoin Tydskrif