Principal Engineer - Classical Cryptography & Architecture

As a Principal Engineer at IonQ (ID Quantique), you own the classical cryptography architecture of post-quantum cryptography (PQC) hardware acceleration products targeting hardware security modules (HSMs) and network-appliance applications. Real-world quantum-safe systems are hybrid systems where classical and post-quantum algorithms operate side by side with careful key management, crypto agility, and migration paths. You become the senior authority for this classical and hybrid layer, working alongside PQC architecture leadership, combining deep classical mastery with solid working command of the post-quantum algorithms and standards the products are built around.

What you'll do

• Own the architecture and implementation strategy of classical cryptographic functions: symmetric ciphers and modes (AES/GCM and beyond), hash functions (SHA-2/SHA-3, HMAC/KDF constructions), RSA/ECC offload, and true random number generation and entropy architecture (SP 800-90A/B/C)
• Define hybrid classical/post-quantum schemes including key establishment, dual signatures, and composite certificates
• Design crypto-agility mechanisms that allow customers to migrate safely to quantum-safe deployments without breaking existing infrastructure
• Track the standardisation of hybrid and composite approaches including NIST guidance, IETF work on hybrid key establishment in TLS 1.3 and IKEv2, and composite certificates
• Guide RTL and software engineers implementing classical cores
• Technically evaluate third-party IP
• Support FIPS 140-3 and CAVP certification of the classical algorithm suite
• Own key-management and key-hierarchy architecture across the product, ensuring interoperability with deployed HSM, TLS, and IPsec ecosystems

What you bring

• A Master's or PhD in Cryptography, Computer Science, Electrical Engineering, or a related field
• At least twelve years of experience implementing and architecting classical cryptography in real products, in hardware, software, or both
• Deep command of symmetric and asymmetric primitives, modes of operation, key management, and entropy generation
• Experience taking cryptographic subsystems through FIPS 140-3 or Common Criteria evaluation
• Solid working knowledge of the NIST post-quantum algorithms (ML-KEM, ML-DSA, SLH-DSA) and their deployment constraints
• Understanding of practical constraints in deployed security infrastructure (HSMs, PKI, TLS, and IPsec ecosystems) and how hybrid classical/post-quantum schemes are standardised and deployed in practice
• Ability to write precise specifications, guide implementers effectively, and make sound architecture decisions under real-world interoperability constraints
• Fluency in English (French or German is an advantage)

What we offer

• Competitive compensation scheme, benefits package, and equity plan designed to reward excellence
• Flexible work models to balance life, family, and career
• Ongoing training and development
• Career development plan within the IonQ group's companies
• Comprehensive medical, dental, and vision plans
• 401(k) matching
• Unlimited PTO and paid holidays
• Parental and adoption leave
• Legal insurance and home technology stipend

About IonQ

IonQ (NYSE: IONQ) is the world's leading quantum platform and merchant supplier delivering integrated quantum solutions across computing, networking, sensing, and security. The company operates globally from offices in Maryland, California, Colorado, Massachusetts, Tennessee, Washington, Italy, South Korea, Sweden, Switzerland, Canada, and the United Kingdom, with quantum computing services available through all major cloud providers. IonQ achieved 99.99% two-qubit gate fidelity in 2025, setting a world record in quantum computing performance.