Smart Contract Audit

Smart contract audits have become a baseline expectation for any serious DeFi protocol seeking user trust. Audit firms (Trail of Bits, OpenZeppelin, Certik, Halborn, Quantstamp, ChainSecurity, Peckshield) review code for known vulnerability classes: reentrancy attacks, integer overflow/underflow, access control failures, oracle manipulation, flash loan attack vectors, signature replay attacks, and business logic errors. A typical audit for a moderately complex DeFi protocol costs $50,000–$300,000 and takes 2–6 weeks.

The limitations of audits are significant and frequently misunderstood. Audits are not guarantees of security — they're reviews of the code as it existed at audit time. Several heavily audited protocols have been exploited: Euler Finance ($197M, March 2023) had been audited by multiple firms. Ronin Bridge ($625M, March 2022) was audited. BadgerDAO ($120M, December 2021) was audited. Most exploits that defeated audits involved either (1) logic errors unique to the protocol's specific business logic that auditors didn't fully model, (2) changes made to the code after the audit, or (3) external dependencies (oracles, bridging logic) that weren't in scope.

Best practices for evaluating audits: check the audit date vs. current deployed code version, verify the audit scope covered all contracts you interact with, read the findings (especially unresolved medium/high severity issues), check if the codebase changed significantly post-audit, and prefer protocols with multiple independent audits from top-tier firms. Resources: Certik's security leaderboard, Immunefi's bug bounty database, and Solodit.xyz (aggregates all public audit reports). Even a perfect audit history doesn't eliminate smart contract risk — it merely confirms diligence was applied.