Senior Security Engineer Cryptography - Trail of Bits

About Trail of Bits

Founded in 2012 by 3 expert hackers with no investment capital, Trail of Bits is the premier place for security experts to boldly advance security and address technology's newest and most challenging risks. It has helped secure some of the world's most targeted organizations and devices. Our combination of novel research with practical solutions reduces the security risks that our clients face from emerging technologies.

The Role

We're hiring a Senior Security Engineer for the Cryptography team to review and strengthen high-assurance software and cryptographic systems used across technology, finance, defense, and blockchain. You will evaluate whether cryptographic designs and implementations deliver the security properties they claim, find subtle failures where theory meets code, and help clients make sound decisions about risk and remediation.

What You'll Do

• Lead cryptographic assessments: Review protocols, libraries, and application code; identify design and implementation weaknesses; validate exploitability; and recommend practical fixes.
• Analyze advanced constructions: Work across standardized symmetric and asymmetric cryptography, post-quantum schemes, zero-knowledge proof systems, and multi-party computation protocols.
• Build useful tooling: Create or extend tools, test harnesses, and proofs of concept that improve cryptanalysis, implementation review, and repeatability across engagements.
• Own clear client delivery: Plan your work, surface risk early, lead technical discussions, and produce precise reports that explain both the finding and the engineering path forward.
• Shape the practice: Contribute to scoping and methodology, mentor other engineers, identify promising research or tooling opportunities, and help turn repeated client needs into stronger services.
• Share what you learn: Contribute to open-source projects and, when appropriate, publish technical work or present it to the security and cryptography communities.

What You'll Bring

• Applied cryptography depth: Substantial experience evaluating cryptographic primitives, protocols, and implementations.
• Mathematical fluency: A foundation strong enough to read relevant academic papers, reason about security assumptions, and translate research into implementation-level questions.
• Code review and development skill: Proficiency in at least one systems or security-oriented language such as Rust, Go, C, or C++, plus experience using Git-based development workflows.
• Assessment judgment: The ability to form and test hypotheses, recognize where specifications and implementations diverge, and prioritize findings by real-world impact.
• Senior-level ownership: A record of independently driving complex technical work, managing ambiguity, and helping teammates improve their approach.
• Client communication: Clear writing and confident technical communication with engineers, researchers, and other stakeholders.
• Collaborative curiosity: A willingness to learn unfamiliar systems, share incomplete ideas early, and work closely with colleagues and clients.

Nice to Have

• Experience assessing post-quantum, zero-knowledge, threshold, multiparty-computation, or privacy-preserving systems.
• Published cryptography or security research, open-source contributions, public audit reports, conference talks, or technical writing.
• Experience designing cryptographic APIs, reviewing protocol specifications, or moving research implementations toward production use.
• Experience scoping security engagements, mentoring engineers, or developing repeatable assessment methodologies.