zkao
- Maintainer
- zkSecurity
- Website
- https://zkao.io
- Category
- Cryptography and ZK specialists
- Targets
- CircomLeo (Aleo)Rust cryptoGo cryptoMPCFHEPost-quantumTLS / E2EE
- Approach
- Multi-agent LLM workflows with expert-maintained skills, a second wave of validating agents, PoC harnesses, and automatic re-scans as models improve
- Access
- SaaS; prepaid non-expiring credits; enterprise plans with human audits
- Status (2026-09-13)
- Active (zkao 2.0 released 2026-07-24)
- First public release
- 2026-02-07
What zkao does
The pipeline has five stages: connect a repository, parse the code, multi-agent deep analysis, validate findings to filter false positives, and report. A first pass of agents reviews the codebase and reports findings, then a second wave reviews those findings; the loop runs repeatedly as 'zkao workflows'. Named flows such as cryptopsy combine implementation analysis with cross-referencing academic literature, and subagents are designed to output knowledge about a module (assumptions, invariants) rather than bug lists. Expert-maintained skills encode patterns from more than a hundred zkSecurity audits. A user-supplied zkao.md threat model file reduces noise: on the HumanityLink engagement it cut false positives from 14 of 33 findings to 2.
The product thesis is that LLM bug finding is non-deterministic, so coverage compounds with repeated runs, and that the harness around the model matters more than raw repetition. Findings are deduplicated across runs and scans re-trigger when models or patterns change. For Aleo, a Rust cheatcode harness called cheatVM turns findings into executable end-to-end proofs of concept. Underlying models are not disclosed on the product pages; case studies mention Claude Opus 4.6 and 4.8, GPT-5.3 and 5.5, and Codex.
Launched in February 2026 with Circom as the first target, zkao added Leo support in July 2026 and zkao 2.0 (24 July 2026) replaced subscriptions with prepaid, non-expiring credits capped per scan. The pricing page lists three tiers by codebase size with median costs of about 49, 281 and 1,112 dollars per scan; project creation is free and sign-in is curated. Enterprise continuous coverage backed by zkSecurity engineers and manual audits is available. Solidity and EVM code are not the focus.
Published results are the reason it leads this category. Cloudflare CIRCL (July 2026): seven confirmed bugs, six awarded under Cloudflare's HackerOne program, including a critical CP-ABE access-control break and a rogue-key BLS aggregate-signature flaw the AI had rated medium. OpenVM (July 2026): a missing subfield membership check on a prover-supplied scaling factor in the pairing guest library that let a malicious prover forge any pairing equality; plain Opus 4.6 and Codex 5.3 runs found only low-severity issues, and zkao found it after more than nine hours of scanning. Bron Labs (July 2026): four zero-days found by a dual-agent auditor and validator pipeline. zkSecurity's own caveat, quoted in the CIRCL post: the AI produced candidate findings, not final reports, and humans validated each issue.
Where it is strong
- Only AI tool with public, upstream-confirmed critical findings in cryptographic libraries and a zkVM.
- Built and validated by a cryptography audit firm; skills encode real audit patterns and a threat-model file measurably reduces false positives.
- Continuous model: prepaid credits, deduplicated re-scans, and an enterprise path to human audits from the same team.
Limits and caveats
- Candidates, not reports: zkSecurity's own posts document mis-rated severities and triage of more than a thousand candidates as the main bottleneck.
- Language coverage is cryptography-first (Circom, Leo, Rust, Go); Solidity and EVM are out of scope.
- Curated sign-in and no free tier; underlying models are not disclosed on the product pages.
When to choose it
Choose zkao when your codebase is cryptographic (circuits, proof-system libraries, MPC, post-quantum, TLS) and you want continuous AI coverage from a team that can also do the human validation. Start with the single-circuit tier on a component with a written threat model, and read the CIRCL and OpenVM posts to calibrate expectations. The maintainer, zkSecurity, is listed first on this index.
Who works with zkao
Listed first because it is the only firm on this index whose AI tooling was built for cryptographic and ZK code, with upstream-confirmed critical results (seven CIRCL bugs, OpenVM CVE-2026-46669, four bron-crypto zero-days), an open benchmark and open skills, and explicit human-in-the-loop validation by cryptographers.
Read the zkSecurity profile · Website
Related tools in Cryptography and ZK specialists
zk-skills and circom-auditor, zkCraft (with zkFuzz), AI Grinding for cryptanalysis (research).