Bridge Security Audit — A bridge security audit reviews how messages and value move between chains: the proof or signature verification on the destination chain, the trust placed in validators and relayers, replay and ordering protection, mint authority limits, and the operational security of the keys that authorise transfers.
Bridges hold more value per line of code than almost any other contract type, and they have lost more of it. The historical pattern is consistent: the cryptography is usually fine, and the loss comes from a verification shortcut, a signature scheme that accepts a message it should not, a validator set that can be changed too easily, or an operational key that was never as cold as the documentation claimed.
We review both halves. On-chain: proof verification, message encoding, replay and nonce handling, mint and unlock authority, and the upgrade path. Off-chain: the relayer and validator architecture, key custody, quorum changes, monitoring, and the specific sequence an attacker would follow to get one fraudulent message accepted.
We fix a commit hash, agree the in-scope contracts and read your architecture docs, then build a threat model: who the actors are, what the trust boundaries are, and which invariants must never break. Nothing is reviewed against assumptions we have not written down.
Line-by-line review by at least two auditors working independently, focused on authorisation, accounting, upgrade paths, external integrations and the gap between what the code does and what the documentation claims it does. Most critical findings come from this phase, not from tooling.
Static analysers appropriate to the language, plus property-based fuzzing and invariant testing to push the system into states no unit test covers. Tooling is used to widen coverage, never to replace the manual pass.
Candidate findings are proven on a forked network with a working proof of concept. We report what an attacker can actually do and what it costs them, not a theoretical severity label.
Every finding gets a severity rating, reproduction steps, the affected code, the impact in concrete terms and a specific remediation. You get a draft for discussion before anything is finalised.
We re-test every remediation against the original proof of concept and check that the fix has not opened a new path. The final report is yours to publish.
| Severity | What it means |
|---|---|
| Critical | Direct loss of funds or permanent freezing of assets, exploitable by any actor. |
| High | Loss of funds or protocol insolvency under realistic conditions, or requiring a privileged actor to misbehave. |
| Medium | Broken protocol behaviour, denial of service, or value leakage that does not directly drain the contract. |
| Low | Edge-case incorrectness with limited impact, or an issue requiring implausible preconditions. |
| Informational | Code quality, gas efficiency, documentation mismatch and defence-in-depth suggestions. |
Single token contract: starts from $999, report in 24–48 hours. dApp, GameFi or RWA project: starts from $2,999. DeFi protocol, L2 / rollup, Bridge, ZK circuit, AI agent / MCP: scoped per project after we have seen the code.
Yes, and we recommend both. Most bridge incidents involve the operational side — key compromise, validator set manipulation, relayer behaviour — rather than a contract bug in isolation.
Yes. We review your application logic and, critically, the assumptions you are making about the messaging layer: delivery guarantees, ordering, replay behaviour and who can forge a message.
By constructing the message an attacker would: reused nonces, cross-chain replays, alternate deployments, and duplicate delivery — then confirming each is rejected on-chain, not merely filtered off-chain.
We model it explicitly: how many keys must be compromised, what an attacker mints, how quickly it is detectable, and what recovery looks like. If the answer is "unlimited and undetectable", that is a critical finding.
A repository or contract address, a commit hash to freeze the scope, whatever architecture or spec documentation exists, and a point of contact who can answer design questions. If documentation is thin we will write our understanding of the system back to you and ask you to confirm it — that step alone catches design-level bugs.
A single token contract is 24–48 hours. A typical dApp or mid-sized protocol runs one to two weeks. Large DeFi systems, L2s, bridges and ZK circuits are scoped per project after we have seen the code. We will give you a fixed timeline with the quote, not an estimate that moves.
Yes. Fix review is part of the engagement, not an upsell. We re-run the original proof of concept against your patched code and confirm the fix has not introduced a new path.
Send the repository and a commit hash through the contact form, message @bugtester25 on Telegram, or book a 30-minute scoping call. 200+ protocols audited · $4B+ secured · 0 hacks post-audit. Prefer email? info@safeedges.in.