Introduction

With the approval of the Bitcoin Spot ETF and the upcoming fourth halving, Bitcoin has experienced a surge, skyrocketing from $43,000 in early February to $73,000, an increase of up to 70%. At the same time, the market has been highly attentive to the ecological construction of Bitcoin, with Bitcoin Layer 2 being highly anticipated. The market expects that this expansion plan will promote the rapid development of the Bitcoin ecosystem and meet the demands of many users.

Bitcoin Price Change (Source: CoinGecko, 2024.03.14)

BEVM: A Promising Bitcoin Layer-2 Project

This article presents the prospective project, BEVM. BEVM is a second-layer Bitcoin network that is EVM-compatible and uses Bitcoin for gas fees. In essence, BEVM has three main characteristics:

1. Decentralized Bitcoin cross-chain mechanism: Users can cross-chain Bitcoin to Layer 2 in a decentralized manner.
2. Compatible with EVM Ecosystem: DApps in the EVM chain ecosystem can seamlessly operate on the BEVM network.
3. Use Bitcoin as a gas fee: Gas fees on the BEVM network are paid with Bitcoin, aligning with the interests of the main network.

It’s worth mentioning that BEVM received angel investment from ViaBTC Capital in mid-February this year. It is currently in the testnet phase with 26 deployed ecosystem projects, including wallets, cross-chain bridges, DeFi, etc. Additionally, BEVM has completed two stages of interactive tasks during the early launch on the testnet, accumulating over 6 million transactions and surpassing 95,000 on-chain users. It plans to launch the mainnet by the end of the first quarter and will also introduce its native token in the future.

BEVM Ecosystem (Source: BEVM Official Website, 2024.03.14)

Technical Framework and Features of BEVM

According to the white paper released by BEVM on GitHub, BEVM has made two significant technical breakthroughs. The first is the decentralized implementation of cross-chain mechanisms for Bitcoin on-chain assets. The second is using Bitcoin as a gas fee while maintaining compatibility with EVM chains. Details on these points are provided below.

How to Implement Decentralized Cross-Chain Mechanisms for Bitcoin On-Chain Assets?

BEVM’s strategy involves deploying Bitcoin light nodes on the chain to synchronize all data from the Bitcoin mainnet. When a user wishes to transfer assets from the Bitcoin mainnet to BEVM, the Bitcoin light node synchronizes the relevant transaction data and proof. A one-way cross-chain interaction is finalized once BEVM’s consensus mechanism verifies this. This system, facilitated by the Bitcoin light node’s data synchronization, guarantees the accuracy and legitimacy of the data, achieving a decentralized cross-chain mechanism.

How can BEVM’s On-chain Assets and Data be Decentralized and Cross-chained Back to the Bitcoin Mainnet?

BEVM uses Taproot technology and PoS consensus mechanism to realize the decentralized cross-chain of BEVM’s on-chain assets and data back to the Bitcoin mainnet. In short, when a user wants to cross-chain assets from BEVM back to the Bitcoin mainnet, the transaction will first be voted on by n consensus nodes on BEVM for validity. Once the vote passes, a Bitcoin mainnet Taproot transaction is generated, and the Taproot transaction is then submitted to the Bitcoin mainnet to complete the asset cross-chain interaction.

It is understood that the PoS consensus mechanism adopted by BEVM has unique features, as it introduces Bitcoin for staking. Therefore, the network can use staked Bitcoin or BEVM native tokens to maintain consensus and security. It is explained as follows:

1. When the market value of staked Bitcoin is much larger than that of staked BEVM native tokens, Bitcoin protects network security.

2. If the market value of staked BEVM native tokens is much larger than that of staked Bitcoin, BEVM native tokens are used for protection.

3. When it’s in between the two, network security will be maintained by both Bitcoin and BEVM native tokens.

In addition, Taproot technology also plays a crucial role in the cross-chain process. It uses Schnorr signatures and MAST contracts to generate n private keys composed of multiple parties, with n supporting up to 1,000, similar to the concept of MPC (Multi-Party Computation), enabling the mechanism of cross-chaining back to the Bitcoin mainnet to achieve greater decentralization and security.

How to Use Bitcoin as a Gas Fee and Maintain EVM Compatibility?

BEVM uses the Substate framework to build its blockchain. Substate is a customizable and flexible framework that can effectively meet different blockchains’ application scenarios and needs. BEVM uses Substate to achieve EVM compatibility and the underlying logic of using Bitcoin as a Gas Fee.

BEVM’s Overall Technical Framework

The overall technical framework of BEVM can be divided into four layers from bottom to top. These are the decentralized interaction layer between the Bitcoin main network and the BEVM chain, the consensus layer combining Aura and Grandpa, the EVM-compatible smart contract layer, and the Dapp layer that supports the Solidity programming language to build Dapps, as shown in the figure below.

BEVM Technical Framework (Source: BEVM White Paper, 2024.03.14)

Three Core Visions of BEVM

Furthermore, BEVM has listed three crucial core visions on its official website, outlining their future development focus:

1. BTC EVM: The construction of a decentralized Bitcoin Layer2 that uses Bitcoin as a Gas Fee and is compatible with EVM. This allows Dapps in the EVM ecosystem to be seamlessly deployed on BEVM, simultaneously increasing the usage and consumption scenarios of Bitcoin.
2. BEVM - Stack: Provides an efficient and cost-effective solution to help development teams or project sides build customizable Bitcoin Layer2.
3. BTC to VM: BEVM plans to build a Decentralized Bitcoin FX Protocol, a decentralized Bitcoin foreign exchange system. The protocol aims to introduce Bitcoin into any blockchain or ecosystem, helping various public chains improve their currency credit.

BEVM’s core vision (source: BEVM website, 2024.03.14)

Conclusion

In essence, BEVM revolves around three key aspects. Firstly, it achieves a decentralized Bitcoin cross-chain through Bitcoin light nodes, the integration of Taproot technology, and the PoS consensus mechanism. Secondly, it lowers the entry barrier and maximizes the attraction of developers and users into the ecosystem by being EVM-compatible. Lastly, it broadens Bitcoin’s use and consumption scenarios by using Bitcoin as a Gas Fee while keeping the interests of miners and the overall Bitcoin community aligned.

At the same time, the BEVM ecosystem has already taken shape, boasting 26 ecosystem projects, over 6 million transactions, and more than 95,000 on-chain users. This makes BEVM a standout among current Bitcoin Layer2 projects. However, as the Bitcoin Layer2 track is still in its early development stages and the competitive landscape continues to evolve, it is worth our continued attention.