Merlin Chain (Merlin)¶

Merlin Chain is a Bitcoin Layer 2 solution designed to bring Bitcoin native assets, users, and protocols into a more programmable ecosystem. It combines multiple scaling technologies, including ZK-Rollup, Optimistic Rollup, and decentralized Oracle networks, aiming to provide EVM-compatible smart contract functionality and high throughput while inheriting Bitcoin's security.

Problems It Solves¶

The Bitcoin mainnet's limited scripting language and low transaction throughput make it difficult to support complex decentralized applications (DApps) and high-performance transactions. Merlin Chain aims to solve:

Insufficient Bitcoin Programmability: Provide a Turing-complete smart contract execution environment for Bitcoin assets without modifying the Bitcoin mainnet.
Scalability Bottleneck: Increase transaction processing capacity in the Bitcoin ecosystem, reduce transaction fees, and improve user experience.
Asset Diversity: Support cross-chain transfers of Bitcoin native assets (such as BRC-20, Ordinals, Atomicals) and their use on Layer 2.
Security and Decentralization: Inherit as much of the Bitcoin mainchain's security as possible in the Layer 2 solution, reducing dependence on centralized components.

Implementation Mechanisms and Principles¶

Merlin Chain adopts a "Hybrid Rollup" architecture, combining the instant finality of ZK-Rollup with the flexibility of Optimistic Rollup.

Asset Cross-Chain and Mapping¶

Users can securely transfer assets on the Bitcoin mainnet (such as BTC, BRC-20, Ordinals) cross-chain to Merlin Chain. These assets are mapped as Layer 2 assets on Merlin Chain for use by smart contracts and DApps. The cross-chain mechanism typically involves multi-signature addresses or zero-knowledge proofs to lock mainnet assets.

Hybrid Rollup Architecture¶

ZK-Rollup (Zero-Knowledge Proof): Merlin Chain plans to use zero-knowledge proof technology to verify the correctness of Layer 2 transactions. By aggregating a large number of off-chain transactions and generating a concise proof (Validity Proof), it submits this to the Bitcoin mainchain for verification, achieving instant finality.
Optimistic Rollup (Optimistic Verification): As a supplement to ZK-Rollup, or as an alternative at certain stages, the Optimistic Rollup mechanism allows transactions on Merlin Chain to be considered valid by default. Correction through on-chain fraud proofs is only required if fraudulent behavior is detected during a specific challenge period.
Data Availability: Merlin Chain uses decentralized Oracle networks (such as Celestia or EigenLayer's data availability layer) to ensure the availability of Layer 2 transaction data, guaranteeing that the raw data needed to generate fraud proofs or validity proofs is accessible.

EVM Compatibility¶

Merlin Chain's virtual machine environment is typically designed to be compatible with the Ethereum Virtual Machine (EVM). This means Ethereum developers can relatively easily port existing DApps to Merlin Chain, thereby accessing Bitcoin's vast asset and user base.

Decentralized Provers and Sequencers¶

Merlin Chain is committed to building decentralized Prover networks and Sequencer networks to avoid single points of failure and censorship risks, ensuring the network's censorship resistance and reliability.

Key Features¶

Bitcoin-Native Security: By ultimately anchoring transaction data on the Bitcoin mainchain (whether through ZK proofs or fraud proofs), Merlin Chain aims to inherit Bitcoin's security.
EVM Compatibility: Lowers the barrier for Ethereum developers to enter the Bitcoin ecosystem, promoting DApp ecosystem growth.
High Scalability: Significantly increases transaction throughput and reduces transaction costs through Rollup technology.
Multi-Functionality: Supports seamless cross-chain transfer of Bitcoin native assets and enables complex DeFi, NFT, GameFi, and other applications on its Layer 2.
Innovative Hybrid Architecture: Combines the advantages of ZK and Optimistic Rollup, balancing performance, security, and development flexibility.