On February 17, CKB Co-founder/Khalani Network CEO Kevin, CKB Ecological Fund CMO/SeeDAO founder Baiyu, and CKB community ambassador CyberOrange shared their views on the UTXO model and its ecology during an X Space live broadcast.
The live broadcast lasted for 1 hour and 40 minutes and contained a lot of information. The following are the key points based on the audio:
1. UTXO 模型和账户模型的区别
Regarding the UTXO model, host Baiyu used a very easy-to-understand metaphor: When you walk on the street, you cannot know how much money the people on the street have in their pockets unless you go through their pockets one by one. In contrast, Ethereum, which uses the account model, has a world state tree, which saves the status of all Ethereum accounts in the world (such as account balances, contract information, etc.).
Kevin added that before Ethereum came out, there was actually only UTXO. In the earliest days, both UTXO and account models were interpreted around assets. Even now, UTXO is still a more pure asset-centered concept or programming intention, because each UTXO is an asset, a portable asset, and script is used to define who it belongs to. . The account model later developed and transformed into assets to serve contracts, and it is fundamentally no longer point-to-point like UTXO, but point-to-point pool. From the perspective of assets, smart contracts are smart custody, and everyone Interact with this smart hosting.
CyberOrange then introduced several major advantages of the UTXO model: First, UTXO naturally supports parallel transaction processing, so its performance ceiling is higher. Secondly, the security level of assets issued on the UTXO chain is the same as that of native coins, because it is also in a UTXO. In comparison, other assets issued on Ethereum (such as ERC-20) are all hosted in smart contracts, and their security level is far lower than that of the native token ETH. Third, the privacy of UTXO will be better. The wallet can change an address every time it is used (the cost of doing this in the account model is very high), and privacy can be further improved with the help of protocols such as Mimblewimble. Fourth, the account model will perform calculations and verification on the chain at the same time, while the UTXO model only performs verification on the chain, making it more suitable to become a settlement layer. In addition, the highest performance expansion solution is the channel network (Channel), which must be based on the UTXO model. It will be extremely difficult to do it on the account model.
2. Cell model
CKB generalized the UTXO model and named it Cell model. Like UTXO, Cell is also a transaction output, but Cell generalizes the amount in UTXO and corresponds to capacity and data, thus turning the original space for storing integers into a space that can store any data. Space.
At the same time, there are LockScript and TypeScript in Cell's data structure. The former mainly reflects ownership, while the latter can customize many rich functions, even most of the functions mentioned in the BIP (Bitcoin Improvement Proposal). In Cell's scripts, developers can also specify cryptographic primitives according to their own needs, which is very flexible.
In short, the Cell model continues the basic philosophy of Bitcoin UTXO, making it easy for the CKB chain to inherit the simple and secure features of Bitcoin. At the same time, through clever modifications, Cell has the ability to support smart contracts.
3. Why is the UTXO ecosystem developing slowly?
Kevin believes that after so many years of development of blockchain, the core is still a decentralized technology that serves assets, and everyone makes applications around assets.
UTXO is a programmable asset. Use script to define the purpose and transfer conditions of this asset. However, when making DeFi applications on the UTXO model chain, how to solve the liquidity on the chain is a relatively difficult point, because UTXO is a It is a portable asset that everyone trades peer-to-peer. It is not easy to find a counterparty that can just meet the needs.
In the blockchain that adopts the account model, everyone puts assets into smart contracts. DeFi applications use smart contracts to aggregate on-chain liquidity and solve the problem of counterparties. Of course, this also brings some risks. For example, a bug in the smart contract may cause the entire fund pool to be rug.
Kevin believes that liquidity is how to program for the future, which is a concept on the timeline, so UTXO also needs this kind of programming paradigm that can span time. UTXO is a sovereign asset, that is, the holder has full control over its ownership. So how can we maintain the characteristics of UTXO and solve the liquidity problem across time? Kevin believes that this requires UTXO assets to express not only ownership, but also how to match up in the future or where to take the assets. He believes that Partially Signed Transactions is a solution. Currently, the Bitcoin community is also studying Partially Signed Bitcoin Transactions (PSBT, partially signed Bitcoin transactions).
In addition, the programming model of UTXO is more complex than the account model. The programming method of the account model is very user-friendly. Developers only need to clarify the logic on the chain and deploy smart contracts, and then they don’t have to worry about it. The off-chain parts are all standard interfaces to connect to smart contracts. Therefore, the blockchain ecology of the account model develops relatively quickly and has many applications, while the blockchain ecology of the UTXO model or the pan-UTXO model develops slowly.
4. Partially Signed Transactions
Partially Signed Transactions can help the UTXO model blockchain realize the functions of financial applications on Ethereum.
Taking exchange as an example, the user holds UTXO assets and then uses Partially Signed Transactions to spell out a transaction that has not yet been uploaded to the chain. This transaction expresses his intention, for example, he wants to exchange 1 BTC for 10 ETH and 59 BNB. Only when his intention is satisfied, the transaction will be uploaded; before it is satisfied, the asset (1 BTC in this example) will always be in his hands.
CyberOrange mentioned that Partially Signed Transactions allow users to do whatever they want with their transactions off-chain, and can also achieve the intent of the entire chain.
On CKB, a solution called Open Transaction is used, which is an off-chain coordination mechanism for constructing transactions. Transaction initiators can complete interesting and complex tasks through off-chain collaboration, and can also divide the transaction structure into multiple Small steps, each corresponding to a different modular solution. Click here to read the popular science introduction of Open Transaction.
5. Benefits of “on-chain verification, off-chain calculation”
Regarding "on-chain verification, off-chain calculation", Baiyu gave a very easy-to-understand metaphor: you go to the store to buy something worth 20 yuan, and in your pocket you have one piece worth 10 yuan, two pieces worth 5 yuan, and five pieces worth 1. Calculate 20 yuan of banknotes yourself (it can be 10 yuan for one piece, 5 yuan for 2 pieces; or 10 yuan for one piece, 5 yuan for one piece, 1 yuan for 5 pieces) and hand it to Boss, boss, please check if the total is 20 yuan.
On-chain verification is actually very simple, but off-chain calculations are much more complex and consume more resources. Kevin believes that only verification is done on the UTXO model chain, and problems are calculated and solved off-chain. This has at least three advantages:
1. The application can implement very simple liquidation logic or verification logic, and because of its simplicity, it is much easier to implement.
2. The application does not need to consider optimization on the chain (protocol layer). There are always smarter people in this world who come up with better transaction matching mechanisms, more applicable price curves, etc. Since the steps of finding counterparties and matching transactions are all implemented by off-chain calculations, only verification is done on the chain, so the application does not need to Consider optimization on-chain. If you use an optimized version of the transaction matching mechanism or price curve on the account model, you need to redeploy a smart contract and allow users to migrate assets there (such as migrating from Uniswap v2 to Uniswap v3). In other words, applications that only perform verification on the UTXO model are future proof.
3. There is no need to consider interoperability issues. Because only verification is done on the chain and calculation is done off-chain, and the “off-chain” here can be on-chain of other blockchains or non-blockchains. No matter where the calculation of a transaction comes from, it is submitted to the chain and the application will verify it.
In addition, Kevin also mentioned that many of the latest generation of applications are also turning to a verification-based paradigm on the chain, with matching off the chain, and there is a trend of protocol platformization.
6. Pan-UTXO ecology has great prospects
During the live broadcast, Kevin mentioned that the most popular entrepreneurial tracks in the Ethereum ecosystem (such as privacy, intent, account abstraction, parallel processing, etc.), from the perspective of UTXO, these entrepreneurial opportunities are actually brought about by the disadvantages of the account model. The UTXO model itself has these characteristics, or they are easy to implement on the UTXO model.
在直播的最后，Kevin 表达了他对泛 UTXO 生态的强烈看好。 铭文火了之后，大家把目光重新聚焦到比特币上，开发者也开始涌入，大家开始琢磨如何在 UTXO 模型上做开发。无论是 Cardano 还是 CKB，其记账模型都是在 UTXO 模型的基础上做的改进，所以很容易和比特币打通，打通之后，这些泛 UTXO 区块链将会迎来非常多的机会，泛 UTXO 生态也会更加繁荣。
#CKB #UTXO #BTC $CKB
