Canton Smart Contract Audit

A Canton smart contract audit is a security review of code deployed to Canton, carried out against the Chain-specific execution environment execution model and written in Daml — covering both the bug classes shared across Chain-specific runtime systems and the failure modes specific to Canton.

Canton is a privacy-enabled network for regulated institutions, where the security question is less "can funds be drained" and more "can a participant see or do something they are not entitled to".

Auditing on Canton

Daml models rights explicitly through signatories, observers and controllers. Most Canton findings are authorisation modelling errors — a party granted observer rights on a contract that reveals more than intended, or a choice controller with broader rights than the business process requires.

We review the Daml model for authorisation and disclosure correctness, sub-transaction privacy, domain and participant trust boundaries, and the integration layer to institutional systems.

What we test that is specific to Canton

Signatory and observer modelling

Parties granted visibility or authority beyond what the business process requires.

Choice controller authority

Choices exercisable by parties who should not be able to exercise them.

Sub-transaction privacy

Information disclosed through transaction structure to participants who should not see it.

Domain and participant trust

Trust placed in domain operators and participant nodes, and what a misbehaving one achieves.

Integration surface

APIs and ledger integrations connecting to institutional systems.

Shared Chain-specific runtime attack surface

Canton runs on Chain-specific execution environment, so it inherits the bug classes below from every system in that family.

Runtime-specific authorisation model

Whatever this chain uses instead of msg.sender — and every check that assumes EVM semantics.

State model and storage assumptions

How state is keyed, who can write it, and what an attacker can cause to be stored.

Arithmetic and serialisation

Overflow behaviour, decoding of untrusted input, and type confusion at the boundary.

Upgrade and governance authority

Who can change the code, how fast, and what the change can reach.

Bridging and external messaging

Trust placed in cross-chain messages, and replay or ordering assumptions.

Liveness and congestion behaviour

What time-sensitive logic does when blocks are full or the network stalls.

Tooling we use on this runtime

Canton contracts are written in Daml. See our Go audit methodology.

How the engagement runs

  1. Scoping and threat modelling

    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.

  2. Manual review

    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.

  3. Static and dynamic analysis

    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.

  4. Exploit-path simulation

    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.

  5. Reporting

    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.

  6. Fix review and re-test

    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.

What you receive

Canton audit: frequently asked questions

What does a Canton/Daml audit focus on?

Authorisation and disclosure: whether signatories, observers and controllers match the intended business rights, and whether transaction structure leaks information to parties who should not have it.

Is this different from a public blockchain audit?

Substantially. The threat model is a permissioned participant exceeding their rights or learning something they should not, rather than an anonymous attacker draining a contract.

Can you work under institutional procurement?

Yes — NDAs, security questionnaires, defined SLAs and evidence packages for internal audit are standard for these engagements.

What do you need from us to start an audit?

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.

How long does an audit take?

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.

Is a re-test included after we fix the issues?

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.

Audits on related chains

Get a fixed quote in 24 hours

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.