Datachain - ELC For Bridge - BSC
Summary
The current audit concerns a light client for the BSC blockchain. In particular, it is aimed at tracking the state of a particular smart contract on BSC and verifying whether its storage contains expected values. It does this by accepting block headers from BSC as input and returning the relevant updated state information. This light client is designed to operate within an enclave, and it functions as an element of the larger Datachain LCP project. Beyond understanding the purpose of the light client, auditors audited the client with reference to the Parlia consensus mechanism as implemented in BSC's [Go node implementation](https://github.com/bnb-chain/bsc/). Also relevant were changes made to BSC's specification over the course of several [BEPs](https://github.com/bnb-chain/BEPs), especially the ones pertaining to the BSC's recent Bohr hard fork. The most severe issue found during this audit is regarding the possibility of malicious validators enabling the finalization of incorrect blocks. Although the likelihood of such an issue being exploited appears to be low on mainnet, it could result in substantial negative impact on the rest of the LCP project. Other issues found were, by comparison, relatively minor in severity. We would like to note that while high-level documentation was extensive, in-code commenting was relatively scarce and could be significantly improved. Test suite coverage can also be improved in order to ensure proper functionality across the board. **Update**: All issues were fixed or acknowledged. The test suite was adjusted in accordance with the fixes. Documentation was improved, though we would recommend further enhancement in order to develop a full suite of documentation.
