Proof systems & circuits
ZK circuits
Proof-system integrations
Transcript construction
Test the cryptographic guarantees your system relies on.
Manual review of zero-knowledge circuits, custom primitives, signature and threshold schemes, privacy-preserving protocols, and post-quantum designs. We separate what the paper claims from what the circuit, protocol, and implementation actually guarantee.
Technology coverage
Cryptographic systems and implementations we review.
We review cryptographic designs and their implementations, including the systems below. During scoping, we agree the claimed guarantees, assumptions, and components to examine.
Primitives & protocols
Signature schemes
Threshold cryptography & MPC
Encryption & key exchange
Privacy protocols
Post-quantum designs
Implementations
Cryptographic libraries
Custom constructions
Protocol integrations
This list is not exhaustive.
Discuss your cryptographic design.
Describe the cryptographic construction and the security properties it must preserve.
What we review
A proof is only as strong as the assumption beneath it.
We review the claim, the construction, and the code. A correct paper does not make a correct circuit, and a correct circuit does not make a safe implementation.
ZK circuits & proof systems
Constraints, completeness, soundness, trusted setup, witnesses, and the gap between the intended statement and what is actually proven.
Custom primitives
New constructions, modified standards, parameter choices, and whether the claimed security reduction still holds.
Signatures, threshold & MPC
Signature schemes, aggregation, threshold signing, multiparty computation, nonce handling, and key generation.
Privacy-preserving protocols
Confidential transactions, anonymous credentials, zkTLS, private computation, and what still leaks under a realistic adversary.
Post-quantum cryptography
Scheme selection, parameter sets, hybrid migrations, and implementation of lattice, hash-based, and other quantum-resistant primitives.
Implementation & composition
Constant-time behavior, side channels, API misuse, randomness, domain separation, and unsafe composition of otherwise sound parts.
Timing
When to schedule a review
While the primitive is still a draft
A new construction, circuit, or protocol is about to be treated as a building block.
Before a privacy feature goes live
Users, counterparties, or regulators will rely on a confidentiality or unlinkability claim.
Before a PQC or scheme migration
The algorithm, parameters, or hybrid transition changes what every caller is trusting.
When primitives are composed
Standard parts are being combined in a new way, and the composition has not been reviewed.
Our approach
How we review your cryptography.
Document claims and assumptions
Agree the scope and claimed security properties. Build a threat model that separates proven guarantees, design assumptions, and dependencies on standards or other components.
Trace how the construction is used
Follow the protocol, circuit, or primitive through the system. Document the properties each flow relies on and how leakage or weakened assumptions could break them.
Review the implementation and write tests
Challenge parameters, composition, and implementation against the claimed properties. Add regression tests to your repo and record results with supporting evidence.
Verify fixes and document conclusions
We always verify fixes through retesting and document which claims hold, fail, or remain unsupported. Tie the principal’s signed opinion to the reviewed commit and evidence.
What you receive
What your team receives.
Findings report
Breaks in the primitive, the circuit, the protocol, or the implementation, with impact and remediation.
Threat model
What is proven, what is assumed, and which guarantees the rest of the system is inheriting. The register includes scenarios blocked by existing controls.
Record of flows and security properties tested
How a weakened assumption, leaked witness, or implementation flaw becomes a practical break, and which properties along that path held.
Invariant register
Each security property, its test result, and supporting evidence.
Security tests in your repo
Regression tests for the reviewed circuit, primitive, or module, ready to rerun after fixes and future changes.
Signed opinion on a reviewed commit
The principal’s conclusions, tied to the reviewed commit, cryptographic claims, and evidence.
Your review team
Meet the specialists
A principal leads each engagement. Your proposal names the specialists assigned to the scope.
Timur Güvenkaya
Founder & Partner
Led a security engineering practice for Rust and non-EVM systems across Substrate and NEAR. Earlier, built vulnerability-detection engines at Invicti used by Fortune 50 and public-sector organizations.
Manuel B. Santos
Specialist Advisor
Cryptography engineer with a Ph.D. in Information Security and 13 published research articles. Worked on post-quantum cryptography at Tectonic and on MPC and zkTLS at Nillion, where he contributed to Nada and wrote technical reports on threshold ECDSA.
FAQ
Frequently asked questions
Do you verify fixes?
Yes. We always provide remediation guidance and verify fixes through retesting. The final report records the remediation status and any unresolved findings.
How is this different from a smart contract or protocol review?
This review checks the cryptographic guarantees those systems rely on, including the construction, assumptions, and implementation. It can run alongside a contract or protocol review when the two depend on each other.
What specifications and test material should we provide?
Provide the specification, claimed security properties, threat model, and relevant papers or security arguments. For a review that includes implementation, we need access to the code during scoping, alongside build instructions, test vectors, and known limitations.
Can you review a custom or unpublished primitive?
Yes. We examine the construction, its security arguments, parameter choices, and implementation within the agreed scope. We identify assumptions or claims the available evidence does not establish.
Do you cover post-quantum cryptography?
Yes. Reviews can cover scheme selection, parameter sets, hybrid classical-plus-PQC deployments, and the implementation of lattice, hash-based, and other quantum-resistant primitives.
Do you review the design, the implementation, or both?
We can review the construction and its security arguments, the implementation, or both. The proposal defines the properties, assumptions, and depth of analysis covered.
Related services
Other ways we can help
Blockchain Protocol & Infrastructure Reviews
Review custom chains, runtimes, nodes, consensus, and bridges beneath the application layer.
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Smart Contract Security Reviews
Find flaws in contract logic, permissions, accounting, and upgrades before they put funds at risk.
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Signing & Custody Security Reviews
Review key generation, signing approvals, key use, and recovery across MPC, HSM, multisig, and custody platforms.
ExplorePut the claim, the circuit, and the code in the same review.
Describe the construction, the guarantee you need to check, and your deadline. We will propose a cryptography review.
Discuss your scope