EVM链扩展比特币，用户体验摩擦如何解决？

Original author: Haotian

Since there is no legitimacy standard for Bitcoin layer 2, there are currently some solutions on the market that directly use the EVM chain as an extension layer, which should be the most ingenious, convenient and efficient quick-start layer 2 solution.

However, there is an awkward situation in the implementation of this type of solution. Wallets such as native Unisat cannot adapt to the EVM chain environment, and a layer of MetaMask needs to be jumped. How to do it? @ParticleNtwrk brings a solution:

Recently, the Bitcoin layer 2 ecology has been very similar to the turbulent Warring States period when heroes were vying for the throne. In addition to the fact that the shortcomings of the Bitcoin mainnets capabilities are deterministic, the layer 2 expansion plans for Bitcoin are dazzling and full of uncertainty. sex. It may be as slow as LN, or as sophisticated and complex as BitVM, or as unknown and confused as client verification. In this process, some project parties took a simple solution:

Since Bitcoins native assets are very important, the EVM chains expansion performance is very advanced, and the pure UTXO chain structure is too complicated, why not directly use the known EVM chain components as Bitcoin layer 2?

From preliminary observation, most projects such as Merlin chain and LumiBit have adopted similar solutions. It is equivalent to accepting the verification and calculation flaws of the Bitcoin main network, using Bitcoin only as the asset settlement layer, and then externally connecting the EVM chain with mature scalability performance consensus, by transferring BTC and its derivative assets to the EVM environment. Effective circulation and management, thereby achieving second-tier expansion.

Normally, the EVM environment supports wallets such as MetaMask, while Bitcoin supports wallets such as Unisat and Xverse. If EVM is used as the second layer of Bitcoin, it means that users’ assets on Unisat need to find a way to migrate to MetaMask. environment, and then use Metamask to connect to the layer 2 network. Such infrastructure conditions will make the user interaction experience extremely poor, and some native Bitcoin users who were brought into the market by Inscription will inevitably have a learning barrier when they come into contact with multi-chain wallets.

This is because the signature algorithm of Bitcoin and the contract parsing function of EVM are not compatible, and forced compatibility will definitely bring about experience friction issues. Based on this, Particle Network launched the BTC Connect account abstraction function that serves the Bitcoin ecosystem, with the goal of allowing users to achieve seamless connection to the EVM chain directly through native Bitcoin wallets such as Unisat. How to do it? In fact, the logic is very simple:

Since Unisat itself has a set of private key generation encryption algorithms, under normal circumstances, EVM native wallets such as Metamask cannot directly parse such algorithms, and then correctly parse them when the DApp calls the users signature.

Particle is equivalent to providing an account abstraction framework. When the user connects to the Unisat wallet, Particle will automatically generate an EVM address for the user on the EVM chain. When the user makes a front-end interactive request on Unisat, Particle will automatically handle the back-end and EVM environment. adaptation.

For example: when a user transfers cross-chain assets from the Bitcoin main network to Merlin Chain, Particle will support the user to transfer a BTC asset to Merlin Chain in a safe manner. After the relevant address receives the asset, it will automatically transfer it to the users corresponding EVM address through the contract. Generate a Wrapped BTC asset for circulation;

Another example: when a user uses Unisat to connect to the Merlin Chain, he wants to perform a Swap operation on Merlin. At this time, Merlin needs to call the users local Unisat private key to generate a signature. Since the Bitcoin signature algorithm is inconsistent with the EVM parsing logic, it may not be possible. can be called correctly. At this time, Particle plays the role of communication protocol, and Merlin will call the private key corresponding to its EVM address. The EVM address then mobilizes the corresponding address private key on Unisat through the Particle account abstract network. The whole process has no user experience.

Completing the compatibility between the Bitcoin native wallet and the EVM environment is only the first step. Since Particles solution is essentially based on the ERC 4337 account abstraction standard, its Smart Account, Paymaster, Bundler, etc. can all achieve some wonderful functions: such as Gas-free transactions, batch Transactions, and communication and interaction with other EVM chain environments. In theory, a BTC wallet can interoperate with the entire EVM chain.

Of course, there are still a series of key issues in this process, and the EVM chain needs to solve the problem of safe cross-chain Bitcoin assets, especially the rich inscription assets other than BTC assets. For example: how to safely cross-chain BTC native assets, how to efficiently record accounts by combining various indexers, how to play the role of inscription DA, how to design the challenge mechanism, etc. In short, the core of second-tier expansion lies more in the widespread circulation and implementation of derivative assets.

To a certain extent, this asset settlement layer solution, which treats Bitcoin as a second-layer extension chain, is not as advanced as native BTC solutions such as client verification and status channels at first glance, but this is not necessarily the case. After all, under the premise that there is currently no orthodox standard for Bitcoin layer 2, based on the principle that existence is reasonable, this type of rapid implementation plan is also exploring a possibility. Do you agree?

In fact, whether you admit it or not, the BTC ecosystem will evolve and develop at a certain pace, and will eventually go in some directions with higher market recognition. For example, it took a long time for Rollup to become the mainstream of Ethereum layer 2.

Anyway, Particle is definitely winning this wave of operations. This kind of integration ability in the chaotic situation with the interoperability of the underlying framework is impressive.