{"id":947675,"url":"https://alion.io/job/cryptonext-security-senior-cryptography-engineer-c-developper","title":"Senior Cryptography Engineer - C developper","company":{"id":6520,"name":"CryptoNext Security","domain":"cryptonext-security.com","url":"https://alion.io/company/cryptonext-security","size_band":null,"is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Workable","truth_index":null},"role":"Security","role_family":"Security","seniority":"senior","employment_type":"full_time","work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Paris, France"],"countries":["FR"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":61000,"max_usd":101000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":38},"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"CI/CD","optional":false},{"name":"GitLab CI","optional":false},{"name":"Linux","optional":false},{"name":"OpenSSL","optional":false},{"name":"QEMU","optional":false},{"name":"Windows","optional":false}],"status":"live","first_seen_at":"2026-09-14T00:00:00Z","employer_posted_date":"2026-09-14","last_verified_at":"2026-10-17T00:30:03Z","board_verified":true,"closed_at":null,"days_open":33,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":33},"description":"Who we are\nCryptoNext Security is a Paris-based start-up founded in 2019, building on more than 20 years of academic research. CryptoNext is a software vendor specializing in quantum-computer-resistant cryptography (PQC: post-quantum cryptography). Its software suite, the Quantum Safe Remediation Suite, includes the world-reference Quantum Safe Library (C-QSL), covering the full selection of NIST algorithms, and helps enterprises and integrators migrate to the era of post-quantum cybersecurity.\nCryptoNext Security was cited among the 5 reference leaders in Gartner’s report on post-quantum cryptography (October 2021) and received the Innovation Prize at «Les Assises 2022». CryptoNext is a member of Campus Cyber, Hexatrust and Systematic, and was selected in 2022 to join a workgroup of the US National Cybersecurity Center of Excellence (NCCoE) dedicated to PQC migration best practices.\nWe are looking for a highly motivated, senior Cryptography R&D Engineer to join our team and take ownership of a key strategic project: porting our post-quantum cryptographic library across multiple platforms, with a particular focus on hardware/software FPGA accelerators. This role sits at the intersection of cryptography, low-level C engineering and embedded/hardware design.\nOn a daily basis, you will\nDesign and implement efficient C code for post-quantum cryptographic algorithms (NIST-selected or recommended by EU agencies), balancing performance, portability and security.\nPort and optimize the CryptoNext Quantum Safe Library (C-QSL) across multiple platforms and architectures\nAdapt implementations for constrained and embedded environments (e.g., IoT, Cortex-M, embedded Linux).\nDefine and run test and validation strategies (functional, performance, security) across all target platforms.\nSupport security certification processes (CSPN, Common Criteria, FIPS) for the ported implementations.\nDocument your work through technical reports and, where relevant, scientific papers.\nCollaborate closely with the R&D team and cross-functional teams to solve complex technical challenges.\nThe CryptoNext Quantum Safe Library is developed mainly in C and Assembly, targeting several operating systems (Linux, Windows, iOS, Android…) and processor architectures (x86, Arm, RISC-V…), as well as FPGA-based hardware accelerators.\nOther tasks may include, depending on your profile and the product roadmap: work on side-channel countermeasures, and collaboration with the team in charge of integrating the library with communication protocols and cryptographic objects (TLS, IPsec, PKCS#11, X.509…) in post-quantum or hybrid mode.\nRequirements\nThe skills you will demonstrate\nSignificant, senior-level experience in cryptography engineering, ideally 5+ years, gained in a software company or department of a larger organization (cybersecurity vendor, IT application or hardware provider), ideally with international teams or clients.\nEngineering degree or Master’s in computer science, mathematics or a related field; a PhD in cryptography or a related discipline is a strong plus.\nSolid foundations in algorithmics and algebra, with the ability to translate mathematical constructs into efficient, correct implementations.\nStrong programming skills in C; comfort working close to the hardware and optimizing for performance and security.\nComfort using embedded development and hardware debugging tools (GCC, GDB, QEMU, JTAG…) and practical experience with source code management and continuous integration using GitLab CI.\nExperience with public-key cryptography, symmetric-key cryptography, hash functions, and cryptographic protocols/frameworks such as OpenSSL is a plus.\nExperience in one or more of the following is a strong plus: embedded software development, hardware/software co-design, FPGA implementation.\nGood French & English communication skills, both oral and written.\nBenefits\nWhat's in it for you at CryptoNext\nOwnership of a strategic, high-impact technical challenge - multi-platform porting and hardware acceleration - at the heart of our product roadmap.\nA fast-growing, globally recognized deep-tech start-up, named among Gartner’s 5 reference leaders in post-quantum cryptography.\nFull-time position, based in Paris.\nCompetitive salary, commensurate with experience.","description_format":"text","description_chars":4287,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"master","optional":false},"security_clearance":false,"languages":[{"language":"English","level":"Upper-Intermediate (B2)","optional":false}]},"benefits":["Hybrid work"],"hiring_locations":[{"name":"France","iso":"FR","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Cybersecurity","Information Security"],"lifecycle":[{"event":"open","at":"2026-09-15T21:56:08Z"}],"visa":[],"liveness":{"score":32,"band":"fade","label":"Fading","p_open":1,"p_active":0.582,"p_room":0.55,"age_days":32,"expected_fill_days":24,"reasons":["conf:0","win:tail"],"computed_at":"2026-10-16T05:45:00Z"},"pay":null,"html_url":"https://alion.io/job/cryptonext-security-senior-cryptography-engineer-c-developper","json_url":"https://alion.io/job/cryptonext-security-senior-cryptography-engineer-c-developper.json","meta":{"generated_at":"2026-10-17T00:44:30Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are real and active right now, what they do and how to work with them, readable by people and by agents and paid per call.","catalog":"https://alion.io/catalog.json","usage":{"tier":"crawler_verified","counted_by":"address","units_charged":1,"used_today":988,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-18T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.02,"usd":0.002,"plus_per_slice":{"credits":0.05,"usd":0.005}},"unit":"per company, plus each slice with data","note":"the employer in depth","call":{"mcp_tool":"get_company","arguments":{"id":6520},"rest":"https://alion.io/mcp/rest/get_company?id=6520"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fcryptonext-security-senior-cryptography-engineer-c-developper"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":1,"usd":0.1},"unit":"per slice","note":"pay, demand and time to fill for this role and place","call":{"mcp_tool":"market_stats"},"human":"https://alion.io/catalog?offer=market.stats&for=job%2Fcryptonext-security-senior-cryptography-engineer-c-developper"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.02,"usd":0.002},"unit":"per posting in a list","note":"similar open postings","call":{"mcp_tool":"search_jobs"},"human":"https://alion.io/catalog?offer=job.search&for=job%2Fcryptonext-security-senior-cryptography-engineer-c-developper"},{"id":"company.verify","title":"Is this company real and active right now","status":"pilot","price":null,"unit":"per company","request":{"url":"https://alion.io/catalog/request","method":"POST","body":"{\"offer\": \"company.verify\", \"for\": \"job/cryptonext-security-senior-cryptography-engineer-c-developper\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fcryptonext-security-senior-cryptography-engineer-c-developper"}]}