On February 26, 2024, Renegade tasked zkSecurity with auditing parts of its circuits and smart contracts. The specific code to review was shared via GitHub as public repositories. The audit lasted 3 weeks with 2 consultants.
You can find the full report here.
We found the implementation, as well as the surrounding documentation and specifications, to be of the highest quality. The Renegade team was very responsive and helpful in answering questions and providing additional context.
Many of us are using AI to generate code. Vibe coding cryptography is especially sensitive - you have to uphold strict mathematical correctness. This can lead to wrong security guarantees and soundness bugs. We will discuss what are some patterns to do it well.
zkVMs are moving to the center of Ethereum's roadmap, which means a bug in a zkVM is turning into a bug in Ethereum itself. We built zkvmBlast, a zkVM-agnostic differential fuzzer that runs the same program across SP1, RISC0, OpenVM, Pico, Zisk, and Airbender against a reference simulator and flags any disagreement. It hunts for both soundness and completeness bugs, with a deliberate focus on completeness, an under-explored class that can turn a single valid block into a liveness failure. We share the first batch of findings.
We are releasing zk-skills, a set of open-source security skills for AI coding agents, starting with circom-auditor: a first line of defense against vulnerabilities in Circom circuits, compatible with both Claude Code and Codex. On the zkbugs benchmark it detects up to 66 of 70 known bugs when pointed at the vulnerable circuits, and up to 40 of 56 when let loose on the full original codebases, far ahead of existing Circom security tools.
We recently teamed up with Celo for an in-depth security audit of the Self project, exploring its innovative approach to on-chain identity using biometric passports and zero-knowledge proofs. During our three-week dive, we examined everything from cryptographic primitives to smart contract architecture and a unique proof delegation system using AWS Nitro Enclaves. The Celo team impressed us with their commitment and responsiveness, and we collaborated on refining the system with strategic improvements. Curious about the nitty-gritty details and our insights? Check out the full report!
Over the past year, we've been diving into whether AI can effectively identify bugs in zero-knowledge circuits and applications, sparking questions about the future of auditing. This led us to develop SnarkSentinel, an AI-powered auditing tool. We'll share what worked, what didn’t, and how our journey with AI could impact auditing. From early challenges with Circom to innovative methods like retrieval-augmented generation and agent-led probing, we'll give you a peek into our findings, including both successes and setbacks with bug detection. Discover how AI might enhance or change the landscape of auditing and what this means for developers and security pros alike.
In June 2025, we uncovered a serious soundness issue in Solana's ZK ElGamal Proof Program that could let attackers manipulate confidential token transfers undetected. We worked with the Anza team to quickly address the flaw by pausing and disabling vulnerable components. This post dives into the root cause, which was a subtle mistake in handling prover-generated challenges within sigma OR proofs, revealing broader lessons in zero-knowledge protocol security. If you're interested in cryptographic protocol design, this could provide valuable insights.
In February 2024, we dived into a security audit of Darkfi's built-in contracts and circuits, putting them under the microscope to ensure everything checks out. Curious to know what we discovered while navigating the public Darkfi repository? Check out our full report for insights and findings.
In this final part of our series on Circle STARKs, we tie together concepts from Mersenne prime fields, circle curves and bivariate polynomials to showcase a comprehensive Circle STARK protocol. We detail the process of arithmetization over the circle curve, introducing Circle FRI as a low-degree test and walk through the complete Circle STARK construction. Readers will explore how trace commitments, constraint batching and low-degree proofs combine for efficient verifiable computation, delving into the nuances of proof validity and security analysis.
Ever wonder how zkApps ensure their execution is spot-on? This post digs into the idea of *boomerang values*, sneaky bugs that can crop up when zkApps mix in-circuit and out-of-circuit logic. We explore how these values disrupt your circuit's trustworthiness, especially when variables are reintegrated unverified. Plus, we share how tools like MIRAI's tag analysis can help spot these issues, making your zkApps more secure. Perfect for anyone into zero-knowledge applications or budding Rust enthusiasts looking for insights on taming complex bugs!