Sky OApp OFT
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About Sky OApp OFT
Sky implements an OFT (Omnichain Fungible Token) adapter for the tokens of the Sky Ecosystem (SKY,USDS, SUSDS and SDAO tokens) using the LayerZero V2 stack to bridge tokens across chains in a standardized manner. Currently, implementations for EVM chains as well as Solana are provided.
Audit Summary
The most critical subjects covered in our audit are functional correctness, correct integration with LayerZero, Denial-of-Service resilience. The general subjects covered are gas efficiency, upgradeability and trustworthiness.
In Version 7 the EVM contracts have been made upgradeable following the UUPS pattern, and the escrow adapter has been extended with a global rate limit shared by all pathways. Notably this token bridge has different security assumptions than the existing native bridges since it relies on the DVN network as oracle and features shared escrowing of funds for different chains. Some general considerations regarding this are provided, in particular:
• Denial of Service.
• Migration Considerations.
• Configuration Considerations.
• Configuration Ordering Considerations.
• LayerZero V2 Considerations.
In summary, we find that the codebase provides a high level of security.
It is important to note that security audits are time-boxed and cannot uncover all vulnerabilities. They complement but don’t replace other vital measures to secure a project.