Forward the Original Title: Technical Deconstruction of CKB Blockchain: Why Can It Accelerate the Development of Orthodoxy BTC Layer 2 Solutions?

TL;DR

Upon hearing that @NervosNetwork is going all-in on becoming a BTC Layer 2 solution, I wasn’t surprised. After all, the CKB blockchain is both similar to and more advanced than BTC. It can inherit the native UTXO features of BTC while also achieving more advanced programmable feature extensions. While it’s almost impossible for CKB to surpass BTC in terms of narrative, if it takes a step back and becomes a Layer 2 solution for BTC, it will be an invincible existence. Why? Let’s talk about my views on CKB in the following.

The current BTC Layer 2 market is limited by the verification capability of the BTC mainnet, which has led to a fragmented landscape. This is because the simplicity of the BTC mainnet’s scripting language, coupled with its near-zero computation and verification capabilities, has given the market ample room and opportunity to play. Currently, apart from limited transaction verification and multi-signature within UTXO unlock conditions, the BTC mainnet cannot directly implement any other complex transaction logic that requires data verification, state changes, etc. Therefore, BTC can only be used as an asset settlement layer, with an additional powerful public chain built to establish local consensus and computational verification capabilities to achieve scalability. As a result, there is no unified standard or “orthodoxy” for the implementation of BTC Layer 2, and it is even difficult to distinguish between different solutions. We can only use the community’s perception to differentiate between narrow and broad definitions:

In a narrow sense, only state channels on the Lightning Network and single-sealed off-chain solutions under RGB can be considered truly orthodox BTC Layer 2 solutions. This is because they fully utilize and leverage the limited scripting verification capabilities of BTC, and require minimal or no off-chain local consensus.

In a broad sense, as long as the local consensus of the off-chain chain is recognized and there is a cross-chain bridge solution to ensure the secure transfer of assets, theoretically any current EVM chain like Ethereum or high-performance chain like Solana can act as a BTC Layer 2.

It is clear that the current BTC Layer 2 market is highly polarized. Either it is extremely narrow, like the Lightning Network and RGB, which are developing slowly and facing many challenges, or it is extremely broad, where any performance chain that can achieve secure asset interaction with the BTC mainnet can be called a BTC Layer 2. So, is there no “middle ground” solution? Yes, the answer is: @NervosNetwork, which adopts the UTXO model at the technical foundation layer and has upgraded its performance for adaptation.

Specific performance:

1) CKB Network and BTC share the same ancestry in terms of ‘UTXO model, mining consensus mechanism’ , which is fundamentally different from the account balance model of mainstream public chains like Ethereum. UTXO has certain unique advantages, such as transaction privacy, flexible transaction construction, and parallel processing to prevent double spending. It can be called Satoshi Nakamoto’s greatest invention. This also explains why Sui and Aptos have adopted similar UTXO models after Ethereum. We can say that Bitcoin’s capacity and block speed are limited by the times, but the UTXO model is very advanced. CKB inherits the UTXO model and optimizes it into the Cell model. This model retains the transaction purity of Bitcoin’s UTXO model while also providing the data state of account models like Ethereum. In layman’s terms, the creation and destruction of Bitcoin’s UTXO model is similar to the process of coins being constantly destroyed and minted. Cell removes the destruction process and aims to verify and permanently store the state. Each Cell contains two fields, Capacity and Data. Capacity is equivalent to the balance of UTXO in bytes; Data stores any form of data, including all historical transaction states. This allows the Cell collection to not only accurately express the balance and process asset transfers, but also contain a series of complex smart contract states. Overall, the Cell model is a leading transaction model with stronger continuity, better flexibility, and the ability to expand the scope of application of the UTXO model. It is also the key for CKB to inherit the security of the BTC mainnet while “accelerating” the slow expansion directions of Bitcoin such as the Lightning Network and RGB.

2) Take the recent launch of RGB++ on CKB as an example. Following the normal process, the difficulty in extending a mature RGB solution to the BTC ecosystem lies not in the one-time sealing process on the BTC mainnet, but rather in the communication, coordination, and joint maintenance of state between off-chain client verification nodes, especially when these nodes are decentralized and distributed. In other words, RGB seems easy in theory, but its practical implementation is hindered by various limitations such as infrastructure, leading to numerous obstacles. CKB sees this clearly and simply allows all these nodes that perform off-chain client verification to participate in the on-chain public verification process on CKB. This directly accelerates the practical path of implementing UTXO extension clients that RGB wants to achieve. After all, it is difficult to reach consensus on complex P2P node networks in an off-chain client environment, which is full of complexity and challenges, such as data synchronization delays or inconsistencies, potential fraud and attack challenges, and so on. If this process can be directly transferred to the on-chain environment, it will be much simpler.

3) RGB++ has been discussed a lot recently. Let me add another point about the Open Transaction data format proposed by CKB, and you will be able to feel the advanced features of this chain. Simply put, Open Transaction allows multiple participants to construct and aggregate different transactions at different times, including three major features: partial construction, modification, incremental construction, and aggregation. For example, Alice creates an Open Transaction, stating that she wants to exchange a certain amount of token A from Bob for token B. After the transaction is initiated, it is still in an editable state. If Bob agrees to the transaction terms after receiving it, he can add his own token B and supplement the transaction terms. It may sound abstract at first. For example, in a cross-chain scenario, Alice and Bob can independently complete asset transactions on different heterogeneous chains, greatly enhancing the cross-chain interoperability of the CKB chain. In complex DeFi transaction scenarios, user participation in DeFi may need to be dynamically adjusted according to market changes. Through Open Transaction, contract participants can flexibly adjust transaction terms during contract execution, which undoubtedly greatly enriches the complex transaction processing capabilities.

In my opinion, Open Transaction and UTXO transaction unlock conditions are exactly the same. They can integrate the construction of complex transaction unlock conditions, multi-party signature participation, and complex application scenarios into a single framework. This is also an innovative value extension that follows the ideology of the BTC main chain. That’s all.

Interestingly, the first project of @busyforking, a member of the Ethereum core development team, actually adopts the UTXO model of BTC. Although the Ethereum smart contract model is now more widely used, Jan and his Nervos team have chosen to extend and upgrade the UTXO model of BTC. This shows their respect for Satoshi Nakamoto’s minimalist UTXO transaction model, and also lays the foundation for CKB to become a native BTC Layer 2 solution.

To sum up, I am very optimistic about CKB as a BTC Layer 2 solution. In the short term, it can indeed accelerate the implementation of Lightning Network and RGB on UTXO model chains. At least it can provide meaningful references for the implementation expectations of these two types of orthodox extension solutions on the BTC mainnet. In the long term, CKB’s native chain features, underlying architecture innovation, and compatibility with other solutions can help it go further in the chaotic and standard-free BTC Layer 2 competition.

Note: There are still many technical details and highlights about CKB that I will analyze further in more detail when I have time. I can’t help but sigh that BTC Layer 2 has given new chains the opportunity to rise from the ground, and it has also given old chains the infinite possibility of sprouting new buds.

Disclaimer：

1. This article is reprinted from [Chain View], Forward the Original Title‘Technical deconstruction of the CKB public chain: Why can it speed up BTC legitimacy layer 2?’,All copyrights belong to the original author [Hao Tian]. If there are objections to this reprint, please contact the Gate Learn team, and they will handle it promptly.
2. Liability Disclaimer: The views and opinions expressed in this article are solely those of the author and do not constitute any investment advice.
3. Translations of the article into other languages are done by the Gate Learn team. Unless mentioned, copying, distributing, or plagiarizing the translated articles is prohibited.