Cybersecurity Engineer, Cryptography

Client: US technology company (digital identity and payments infrastructure) · Location: remote, LATAM, US Eastern overlap · Level: senior · Engagement: full-time contractor You will own applied cryptography across the product: key management, protocol design review and the migration plan to post-quantum algorithms. What you will do - Design and operate key management on HSMs and cloud KMS, including rotation, escrow and ceremonies - Review protocol and feature designs for correct use of encryption, signatures and key exchange - Run PKI: certificate authorities, issuance automation and mTLS between services - Build the crypto inventory and lead the roadmap to NIST post-quantum standards (ML-KEM, ML-DSA) - Maintain internal crypto libraries and guidance so product teams do not roll their own - Support audits and certifications such as FIPS 140-3, PCI DSS and SOC 2 What you bring - 6+ years in security engineering, 3+ focused on applied cryptography - Solid command of modern primitives and protocols (AES-GCM, ECC, TLS 1.3, Noise, JOSE) - Hands-on HSM and KMS experience (Thales, AWS CloudHSM, AWS KMS or equivalent) - Coding in Go, Rust or C, with secure coding and code review experience - Ability to explain cryptographic risk to non-specialists in English Nice to have - Threshold signatures, MPC or zero-knowledge proof experience - Degree or research background in cryptography - Contributions to open-source crypto libraries Originally posted on Himalayas