BTC L2 Summer? An overview of the characteristics, advantages and disadvantages of the mainstream Bitcoin L2 protocol

Author: Hamster; Source: Chainfeeds

The rise of Bitcoin Inscription has injected new vitality into the Bitcoin ecology and has rekindled people's attention to Bitcoin, which has also given rise to many new Bitcoins. Second-layer currency projects, such as Merlin, Bison, Bouncebit, NuBit and BitLayer, etc.

This article selects four relatively popular projects in the market: BEVM, Merlin, B² Network, and BounceBit for interpretation. What are the highlights and advantages of each?

Key points

• Merlin Chain As a ZK Rollup BTC Layer 2 network, Through Chain-Agnostic's account system and the BTC Connect technology provided by Particle Network, seamless mapping between BTC and EVM addresses is achieved, providing users with an efficient and secure cross-chain interaction experience.

• B² Network  is the first network to implement ZPVC on Bitcoin, using ZK-Rollup technology and combining it with the zkEVM solution. Process user transactions and output relevant certificates. B² Network's technical architecture includes the Rollup layer and the DA layer, aiming to transform Bitcoin into a feature-rich multi-platform.

• BEVM  It is an EVM-compatible BTC Layer 2 solution that utilizes Bitcoin’s Taproot upgrade and adopts Schnorr signature and MAST technology. Supporting the use of BTC as Gas demonstrates its rich application scenarios and high ecosystem compatibility.

• Bouncebit Built an infrastructure based on BTC heavy pledge, using dual-token PoS L1 to achieve full compatibility between Bitcoin security and EVM. This ecosystem combines CeFi with DeFi to provide BTC holders with earning opportunities across multiple networks.

Detailed introduction

Merlin Chain: Based on zkEVM technology, currently the highest TVL

The emergence of Merlin Chain marks the birth of a new BTC L2 solution, which aims to Through a series of technological innovations, the scalability, transaction efficiency and security of the BTC network are improved, while network congestion problems are solved. As a ZK Rollup BTC L2 network, Merlin Chain not only supports a variety of native Bitcoin assets, but is also compatible with EVM, demonstrating a design concept that takes into account both the Bitcoin and Ethereum ecology.

The core of Merlin Chain’stechnical framework lies in its chain-agnostic account system and the BTC Connect technology provided by Particle Network. These innovations not only facilitate the seamless mapping between BTC and EVM addresses, but also bring users an efficient and secure cross-chain interaction environment. With the help of multiple technical means such as smart contracts, signature abstraction, and decentralized oracles, Merlin Chain can achieve rapid bridging and transaction processing of native assets, thereby ensuring the overall security and trustworthiness of the ecosystem.

Merlin Chain developed the zkEVM Layer2 solution based on the Polygon CDK framework. It cleverly uses ZK-Rollup technology to effectively compress and verify large amounts of transaction data, greatly improving transaction processing speed and Network Scalability. By integrating sequence nodes, Merlin Chain is able to handle higher transaction volumes. Compressed data, ZK state roots and proofs generated using zkEVM technology are securely uploaded to Bitcoin’s L1 Taproot via a decentralized oracle network, enhancing the overall transparency and security of the network.

Under the technical architecture of Polygon CDK, Merlin Chain adopts a solution called CDK Validium, which combines Polygon zkEVM technology and the concept of DAC, aiming to Implement multi-signature validity verification on the Ethereum chain. This multi-signature method echoes BTC’s Taproot technology, so the decentralized oracle on the Merlin Chain essentially serves as the DAC. The task of Merlin Chain's sequencer is to collect users' transaction data, package and verify it, and then hand it over to ZKP (zero-knowledge proof) aggregator and Prover for processing. This process is supported by Lumoz's ZK-POW function. These L2 transaction data, including hashes and signatures, are transmitted to the BTC network via a decentralized oracle network.

Through this technical layout, Merlin Chain realizes a safe and efficient cross-chain interaction method, allowing seamless connection of transaction data between BTC's L1 and L2 solutions based on zkEVM technology . This architecture not only strengthens the security and transparency of the network, but also opens up new possibilities for interoperability between Bitcoin and other blockchain ecosystems, greatly improving the overall performance and user experience of the system.

Merlin Chain has established interconnections with more than 40 public chains, simplifying the experience for users who are not familiar with BTC, allowing them to interact with familiar wallets (such as MetaMask) and assets. At the same time, Merlin is the only self-developed BTC cross-chain bridge, supporting BTC, BRC-20, BRC-420, Bitmap, Ordinals, and will soon support Atomics, Stamp and later Runes, and also supports ETH, Assets such as Arbitrum, Manta, and Tron.

B² Network: Adopting a double-layer structure, the first network to implement ZPVC Rollup

Similarly as BTC L2, B² Network introduces ZKP's Rollup technology. This technology aims to increase transaction processing speed and expand the diversity of application scenarios, all without sacrificing security. B² Network has become the first network to implement Zero-Knowledge Proof Verification Commitment (ZPVC) Rollup on BTC. By adopting ZKP and Taproot's challenge-response mechanism, it not only supports Turing-complete smart contracts, but also ensures the privacy and security of transactions.

This so-called ZPVC uses ZKP to enhance the security and efficiency of BTC Layer 2. Through ZPVC, B² Network is able to take advantage of BTC’s secure consensus by ensuring the authenticity and integrity of transactions through a challenge mechanism without directly verifying each proof. This approach not only improves the efficiency of processing transactions, but also maintains the decentralized nature and security of the network.

The B² Network architecture is divided into two main layers: the Rollup layer and the Data Availability (DA) layer.

The Rollup layer consists of a variety of components, including account abstraction, RPC service, Mempool, sequencer, zkEVM, aggregator, synchronizer and proof generator, etc. This layer is responsible for receiving, storing, sorting and processing user transactions, and verifying the authenticity of transactions by generating ZKP. This series of steps not only ensures the security of transactions, but also ensures the availability of data, allowing developers to build secure DApps on the B² network, including DeFi, NFT, etc., and supports migrating DApps from other EVM-compatible chains to the B² network .

The DA layer includes decentralized storage, B² nodes and the BTC network. It is mainly responsible for permanently storing Rollup data copies, verifying Rollup’s ZKP, and final confirmation on the BTC network. Decentralized storage ensures the persistence and accessibility of data; B² nodes perform various network operations, such as verification, sorting, and data packaging; the BTC network is responsible for final confirmation of transactions, ensuring the security and inaccessibility of the system. Tamperability. These three parts work together to greatly improve the efficiency and scalability of the network while retaining its decentralized nature.

BEVM: Decentralized through Taproot consensus, compatible with Ethereum ecological DApp

BEVM (Bitcoin Ethereum Virtual Machine) is a decentralized, EVM-compatible BTC Layer 2 solution based on Taproot upgrade. It allows the use of BTC as gas for transactions, and allows DApps in the Ethereum ecosystem to run on the BTC network, bringing a wider range of application scenarios to BTC.

In terms of technical architecture, BEVM uses Taproot consensus, combines Bitcoin’s native Taproot technology stack and the BFT PoS network composed of Bitcoin SPV nodes, creating a decentralized BTC L2 solution plan. Taproot consensus consists of three parts: Taproot technology (including Musig2, Schnorr signatures, MAST, etc.), a BFT PoS network composed of Bitcoin SPV, and threshold node communication formed through the Signal protocol. This architecture improves the scalability and privacy of the Bitcoin network, and at the same time improves the efficiency of Bitcoin network transactions through the batch verification processing of BEVM technology.

Schnorr signatures provide a more efficient and private way to sign, allowing the aggregation of multiple signatures, reducing transaction size and fees. MAST improves the privacy and efficiency of smart contracts by allowing contracts containing multiple execution paths to be deployed on the blockchain without only revealing the data of the actual execution paths, thereby improving data privacy and scalability. Together, these technologies improve transaction efficiency and privacy protection on BEVM. In addition, BEVM uses BTC light nodes as verification nodes and relies on network consensus to achieve the management and use of BTC, thereby achieving true decentralization. The block generation node of the BEVM network also serves as the guardian node of the Bitcoin main network, automatically executing transactions through network consensus, ensuring the security and decentralization of BTC management and cross-chain processes.

In order to simplify the startup and operation process of BEVM nodes, BEVM provides an intuitive and simple node deployment process through the Spheron service. Users can easily recharge Spheron wallets, select BEVM test nodes, configure recommended resources and new wallet addresses, etc., thereby ensuring smooth deployment and efficient operation of nodes.

Bouncebit: Dual-token PoS consensus mechanism

In Bouncebit’s official documents, itclaims to be a "PoS L1", but it is a heavy pledge Infrastructure, which provides a base layer for different heavily collateralized products, is also considered by the market to be a unique second-tier solution.

BounceBit introduces an asset-driven PoS Layer 1 method, strengthening network security through a dual-token system of BTC and BounceBit native tokens, different from regular Layer 2 solution, which achieves interoperability with EVM-compatible chains and combines CeFi technologies, such as Mainnet Digital custody and Ceffu's MirrorX technology, to improve transaction transparency and liquidity, and enhance the flexibility and application scenarios of Bitcoin assets.

Its dual-token PoS consensus mechanism supports 50 validators, optimizing validator election and reward distribution through smart contracts and Epoch-based timelines, while allowing validators to charge commissions on rewards and balance node operations. Costs and benefits jointly create a safe and efficient blockchain ecosystem.

Summary

BEVM, Merlin Chain, B² Network and BounceBit all improve BTC’s scalability, transaction efficiency and diverse application scenarios through unique technical solutions sex. BEVM is characterized by its EVM compatibility and ecosystem construction; Merlin Chain innovates in cross-chain interactive experience; B² Network strengthens transaction privacy through ZKP technology safety and security; while BounceBit adopts a dual-token PoS consensus mechanism, using pledged BTC and native tokens to strengthen network security, and at the same time Provide full EVM compatibility and expand the application areas of BTC.

In addition, BTC L2 is showing a state of blooming, just like the previous ETH L2 season. In addition to the above four public chains, there are also second-layer solutions such as NuBit and BitLayer

strong>, the joint efforts of these platforms herald that BTC L2 solutions will reach new heights in scalability, transaction efficiency, security and ecosystem diversity in the future, promoting BTC to be more widely integrated into the growing blockchain Application areas.

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