Sr Applied Scientist, Cryptographic Libraries

Applied Scientist, Amazon Cryptographic Libraries

The Amazon Cryptographic Libraries (ACL) team builds the cryptography that AWS services and a growing open-source community depend on, including AWS-LC, our FIPS-validated open-source cryptographic library. As an Applied Scientist on the team, your primary focus will be formal verification: building machine-checked proofs that cryptographic implementations are correct. You will also contribute to algorithm implementation, assembly level optimization, and the adoption of post-quantum cryptography.

You will work alongside senior scientists on the team, building deep expertise in an environment where your proofs and code ship to effectively every AWS service. This is a role where an early-career scientist gets both rigorous mentorship and immediate production-scale impact.

Key job responsibilities:

• Develop and maintain machine-checked proofs of correctness for cryptographic implementations in AWS-LC.
• Specify the functional behavior of low-level cryptographic code (Rust, C, assembly) in formal notation and verify it using both automatic and interactive provers, such as HOL-Light, Verus and CBMC.
• Apply formal methods, program analysis, and rigorous testing to raise the assurance bar of a security-critical, widely deployed codebase.
• Contribute to the implementation and optimization of cryptographic algorithms, including post-quantum algorithms (ML-KEM, ML-DSA, SLH-DSA) for production use.
• Assist in the career development of others, actively mentoring individuals and the community on advanced technical issues.
• Publish patents and peer-reviewed articles and present your research both internally and externally.

A day in the life:

You take a cryptographic algorithm that needs to be provably correct and write the formal specification of its behavior, the code and the proof of correctness. You develop the proof in an interactive theorem prover, assisted by state-of-the-art AI models and iterate until the machine checks it end to end. Some days you are debugging a proof obligation; other days you are reading a paper on a new verification technique or helping refine an algorithm implementation, so it is both fast and amenable to proof.

Your proofs back code that is validated for FIPS and deployed across AWS.

About the team:

ACL owns AWS-LC (Amazon's FIPS-validated cryptographic library) and manages third-party cryptographic libraries. We build the cryptographic foundation under nearly every AWS service and a growing set of external open-source projects. Applied Scientists on the team own algorithm-level and assembly performance work and partner deeply with AWS's Automated Reasoning Group on formal verification.