Senior Cryptography Engineer

As a Staff Cryptography Engineer at ID Quantique (part of IonQ), you will implement the software side of modern post-quantum cryptography (PQC) algorithms for HSM and network-appliance products. You will work hands-on at the heart of applied cryptography, building reference models, optimised implementations, and test infrastructure alongside some of the most experienced cryptographic engineers in the field.

What you'll do

• Implement reference models, optimised software implementations, and test-vector infrastructure for ML-KEM, ML-DSA and SLH-DSA/LMS in C/C++/Rust and Python
• Develop constant-time software implementations of cryptographic functions
• Build known-answer-test and test-vector tooling (NIST ACVP) used for verification and CAVP certification
• Decompose algorithms into hardware-friendly building blocks including Keccak, NTT and polynomial arithmetic, samplers, and encode/decode functions
• Support RTL and firmware engineers with algorithm expertise, debugging, and certification-oriented tooling
• Evaluate third-party cryptographic libraries under the guidance of senior cryptography engineers

What you bring

• A Master's degree in Cryptography, Mathematics, Computer Science or a related field
• At least 5 years of hands-on experience implementing cryptographic algorithms or security-critical software in C/C++ or Rust
• Solid understanding of modern cryptographic primitives
• Strong focus on correctness and the ability to write well-tested, readable code
• Understanding of constant-time implementation and why it matters
• Fluency in English

Nice to have

• A PhD in Cryptography, Mathematics, Computer Science or related field
• First exposure to post-quantum schemes (lattice-based or hash-based) and their underlying mathematics
• Familiarity with NIST test-vector formats, CAVP/ACVP or certification-oriented development
• Fluency in French or German

What we offer

• Competitive compensation, benefits package, and equity plan
• Flexible work models to balance life, family, and career
• Ongoing training and development
• Career development plan within the IonQ group
• Comprehensive medical, dental, and vision plans
• Matching 401(k), unlimited PTO and paid holidays
• Parental and adoption leave, legal insurance, and home technology stipend

About ID Quantique

ID Quantique (IDQ), part of IonQ, is a global leader in quantum-safe communications protecting governments, telecommunications infrastructures, and banking and financial institutions from the "harvest-now, decrypt-later" threat. IonQ is the world's leading quantum platform company, backed by major cloud providers and enterprise customers including Amazon Web Services and AstraZeneca, with operations across North America, Europe, and Asia-Pacific.