Senior Cryptography Engineer

About IonQ:

IonQ, Inc. [NYSE: IONQ] is the world’s leading quantum platform and merchant supplier - delivering integrated quantum solutions across computing, networking, sensing, and security. IonQ’s newest generation of quantum computers, the IonQ Tempo, is the latest in a line of cutting-edge systems that have been helping customers and partners including Amazon Web Services,andAstraZeneca achieve 20x performance results and accelerate innovation in drug discovery, materials science, financial modeling, logistics, cybersecurity, and defense. In 2025, the company achieved 99.99% two-qubit gate fidelity, setting a world record in quantum computing performance.

Headquartered in College Park, Maryland, IonQ has operations in California, Colorado, Massachusetts, Tennessee, Washington, Italy, South Korea, Sweden, Switzerland, Canada, and the United Kingdom. Our quantum computing services are available through all major cloud providers, while we also meet the needs of networking and sensing customers across land, sea, air, and space. IonQ is making quantum platforms more accessible and impactful than ever before.

Location: This role is based onsite in Geneva, Switzerland.

Travel:

Job ID: 1893

ID Quantique (IDQ), part of IonQ, is a global leader in quantum-safe communications. We provide solutions to protect governments, telecommunication infrastructures, and banking & financial institutions from the “harvest-now, decrypt-later” threat, delivering both terrestrial and space-based quantum-safe networks in live operation globally.

The Role:

We are looking for a Staff Cryptography Engineer to join our team building post-quantum cryptography (PQC) hardware acceleration for HSM and network-appliance products. You will implement the software side of modern post-quantum algorithms: reference models, optimised implementations, and the test infrastructure that proves they are correct. This is a hands-on development role at the heart of applied cryptography, working with some of the most experienced cryptographic engineers in the field.

Responsibilities:

You will implement and maintain reference and bit-accurate models of ML-KEM, ML-DSA and SLH-DSA/LMS in C/C++/Rust and Python, develop constant-time software implementations of cryptographic functions, and build out the known-answer-test and test-vector tooling (NIST ACVP) used for verification and CAVP certification. You will contribute to the decomposition of algorithms into hardware-friendly building blocks (Keccak, NTT and polynomial arithmetic, samplers, encode/decode), support RTL and firmware engineers with algorithm questions and debugging, and help evaluate third-party cryptographic libraries, working under the guidance of our senior cryptography engineers.

• Implement reference models, optimised software and test-vector infrastructure for ML-KEM, ML-DSA and SLH-DSA/LMS
• Support hardware and firmware teams with algorithm expertise, debugging and certification-oriented tooling

Requirements:

We are looking for a candidate with a Master’s degree (PhD a plus) in Cryptography, Mathematics, Computer Science or a related field and at least five years of experience implementing cryptographic algorithms or security-critical software in C/C++ or Rust. You have solid understanding of modern cryptographic primitives and ideally first exposure to post-quantum schemes (lattice-based or hash-based) and their underlying mathematics.

You care about correctness and write well-tested, readable code; you understand what constant-time implementation means and why it matters. Familiarity with NIST test-vector formats, CAVP/ACVP or certification-oriented development is a plus. Fluency in English is required; French or German is an advantage.

• Hands-on developer of cryptographic or security-critical software with strong C/C++/Rust skills
• Solid cryptographic foundations with the ambition to build deep post-quantum expertise

Preferred Qualifications:

You want to grow into a world-class applied cryptographer by working on real products with demanding correctness and security requirements, and you enjoy the discipline of code that must be provably right.

What We Offer:

• A role at one of the fastest growing and most exciting quantum companies in the world
• A competitive compensation scheme, benefits package, and equity plan designed to reward excellence
• Flexible work models that let you balance your life, your family, and your career
• Ongoing training and development to keep your skills sharp and your growth on track
• A career development plan within the IonQ group’s companies
• A dynamic, close-knit environment where you collaborate with a global team of experts
• A performance-driven culture built on trust, teamwork, and shared ambition

Compensation will vary based on individual factors such as education, qualifications, and experience of the final candidate(s), specific office location, and calibration against relevant market data and internal team equity. Posted base salary figures are subject to change as new market data becomes available. Our benefits include comprehensive medical, dental, and vision plans, matching 401(k), unlimited PTO and paid holidays, parental/adoption leave, legal insurance, and a home technology stipend. Details of participation in these benefit plans will be provided when a candidate receives an offer of employment.

At IonQ, we believe in fair treatment, access, opportunity, and advancement for all while striving to identify and eliminate barriers. We empower employees to thrive by fostering a culture of autonomy, productivity, and respect. We are dedicated to creating an environment where individuals can feel welcomed, respected, supported, and valued.

We are committed to equity and justice. We welcome different voices and viewpoints and do not discriminate on the basis of race, religion, ancestry, physical and/or mental disability, medical condition, genetic information, marital status, sex, gender, gender identity, gender expression, transgender status, age, sexual orientation, military or veteran status, or any other basis protected by law. We are proud to be an Equal Employment Opportunity employer.

US Technical Jobs. The position you are applying for will require access to technology that is subject to U.S. export control and government contract restrictions. Employment with IonQ is contingent on either verifying “U.S. Person” (e.g., U.S. citizen, U.S. national, U.S. permanent resident, or lawfully admitted into the U.S. as a refugee or granted asylum) status for export controls and government contracts work, obtaining any necessary license, and/or confirming the availability of a license exception under U.S. export controls. Please note that in the absence of confirming you are a U.S. Person for export control and government contracts work purposes, IonQ may choose not to apply for a license or decline to use a license exception (if available) for you to access export-controlled technology that may require authorization, and similarly, you may not qualify for government contracts work that requires U.S. Persons, and IonQ may decline to proceed with your application on those bases alone. Accordingly, we will have some additional questions regarding your immigration status that will be used for export control and compliance purposes, and the answers will be reviewed by compliance personnel to ensure compliance with federal law.

US Non-Technical Jobs. Due to applicable export control laws and regulations, candidates must be a U.S. citizen or national, U.S. permanent resident (i.e., current Green Card holder), or lawfully admitted into the U.S. as a refugee or granted asylum. Accordingly, we will have some additional questions regarding your immigration status that will be used for export control and compliance purposes, and the answers will be reviewed by compliance personnel to ensure compliance with federal law.

If you are interested in being a part of our team and mission, we encourage you to apply!