A smart contract audit service provides checks for known vulnerabilities that apply to each smart contract's particular business logic. It also assesses conformance with the Solidity Code Style Guide and verifies that the smart contract is free of logical and access control concerns. Standards for smart contract security audits vary from project to project. Smart contracts can be audited using manual or automated approaches, as discussed below.
Manual auditing entails a group of experts/auditors looking over each line of code for compilation and re-entry problems. This can also aid in detecting other security vulnerabilities that are often overlooked, like poor encryption practices.
On the contrary, the automated smart contract auditing approach uses bug detection software, which helps smart contract auditors locate the exact location responsible for errors. The projects that require faster time-to-market often prefer an automated approach because it helps find vulnerabilities much faster. However, automated software may not always understand the context and can miss vulnerabilities while checking code.