LayerZero: Technical Principles and Evaluation of the Cross-Chain Interoperability Protocol

1. LayerZero Technology Principles

1.1 Overview

LayerZero is a trustless cross-chain communication protocol. It utilizes a lightweight node mechanism, sharing the trust layer through relayers and oracles, achieving better security at a lower cost. LayerZero primarily provides cross-chain messaging functionalities, supporting upper-layer asset cross-chain applications as a foundational protocol.

1.2 Ultra-light Node

Ultra-light nodes (ULN) perform the same validation as on-chain light nodes, but do not retain all block header data in order; instead, they are streamed on demand by decentralized oracles. This reduces storage costs but also incurs some loss of security. However, in certain scenarios, such as social protocols, this trade-off is acceptable.

1.3 Core Roles: Oracle and Relayer

Oracle( is responsible for providing the timing and results of verification to the target chain. Relayer) is responsible for providing the proof process and specific cross-chain information required for verification.

The oracle transmits the Blockhash and Block Receiptsroot of the cross-chain request on the source chain. The relayer transmits the Receipt and Merkle Proof path information for verification. The two work together to achieve the trusted transmission of cross-chain information.

2. LayerZero's Cross-Chain Lifecycle

1. The user application initiates a cross-chain request
2. The communicator packs the request information
3. The validator forwards to the network layer and the relayer.
4. The oracle obtains the source chain block header
5. The relay acquires transaction proof
6. The oracle and the relay send information to the target chain.
7. The target chain verifies the information and performs cross-chain operations.

During the whole process, the source chain charges a Gas fee, and the target chain executes 3 transactions: ( relay, oracle, and executor ).

3. Evaluation of the Advantages and Disadvantages of LayerZero Protocol

( 3.1 Security Considerations

LayerZero allows applications to customize relayers and oracles, forming a many-to-many selection pattern that reduces the risk of single points of failure. At the same time, the protocol itself does not store funds and data, reducing the attack surface. It has now passed multiple rounds of security audits and established a high bounty for vulnerabilities.

) 3.2 Advantages

• Extremely low cross-chain verification costs
• Strong universal extensibility, supporting more inter-chain interoperability.
• Simplified developer onboarding process
• Relieve the problem of multi-chain asset fragmentation

![Cross-chain Track Research Report: Why is LayerZero's Full Chain Interoperability Protocol Valued at 3 Billion USD?]###https://img-cdn.gateio.im/webp-social/moments-73922af3d773eb02d833eaf936b01437.webp###

( 3.3 Challenge

• Highly reliant on the security of the oracle
• The lack of historical block data may pose certain security risks.

Overall, LayerZero, as a foundational cross-chain communication protocol, provides important infrastructure support for the multi-chain ecosystem. Its innovative design strikes a good balance between efficiency, cost, and security, laying the groundwork for the development of future cross-chain applications.

![Cross-Chain Track Research Report: What Makes LayerZero's Full Chain Interoperability Protocol Valued at 3 Billion USD?])https://img-cdn.gateio.im/webp-social/moments-5c39ecae3a9e7b8aa8c8f6e43e560669.webp###