Discussion on the Security of Cross-Chain Protocols: Taking LayerZero as an Example

In the Web3 space, the security issues of cross-chain protocols have become increasingly prominent. In recent years, losses caused by cross-chain protocols have ranked first among various security incidents, and their importance even surpasses that of Ethereum scaling solutions. However, the public's awareness of the security levels of these protocols remains insufficient.

Some cross-chain protocols adopt a simplified architecture design, such as using Relayers to execute communication between Chain A and Chain B, supervised by Oracles. This design does bring a "fast cross-chain" user experience, but it also carries potential risks.

The main issues include:

1. Simplifying multi-node verification to a single Oracle verification significantly reduces the security factor.
2. Assuming that the Relayer and Oracle are always independent, this trust assumption is difficult to maintain in the long term.

Some protocols allow multiple parties to run relays, but this permissionless design does not equate to true decentralization. Increasing the number of trusted entities does not fundamentally solve security issues, and may instead introduce new risks.

For example, if a project allows modification of configuration nodes, an attacker may replace them with their own nodes, thereby forging messages. In this case, projects using this protocol may face serious security risks, especially in complex scenarios.

It is worth noting that some projects claiming to be "infrastructure" are actually more like middleware. True infrastructure should provide consistent security for all ecosystem projects, rather than shifting the responsibility to external applications.

Some security teams have pointed out potential vulnerabilities in certain cross-chain protocols. For example, there is a risk of sending fraudulent messages or modifying messages after they have been signed, which could lead to the theft of user funds.

Reviewing the Bitcoin white paper, we can see that decentralization and trustlessness are the core concepts of cryptocurrency. A true decentralized cross-chain protocol should adhere to these principles and avoid reliance on trusted third parties.

However, some projects, although they claim to be decentralized, still rely on specific roles not colluding to do harm or require users to trust the application developers. This design contradicts the "Satoshi consensus" and is difficult to be considered truly decentralized and trustless.

In the future, the development direction of cross-chain protocols should be to achieve true decentralized security. Only with sufficient resistance to attacks can it thrive in the Web3 ecosystem. Some innovative technologies, such as zero-knowledge proofs, may provide new ideas for enhancing the security of cross-chain protocols.