Cryptography Engineer

As a Senior Cryptography Engineer at Araxi Group, you design, implement and integrate secure cryptographic solutions for payment and financial systems. You combine applied cryptography, backend software engineering, HSMs and payment security, with the ability to translate technical standards into reliable production systems.

What you'll do

• Design and implement cryptographic services and backend components
• Integrate applications with enterprise HSMs and cryptographic infrastructure
• Implement key management and key lifecycle processes
• Work with payment cryptography, including PIN blocks, DUKPT, CVV/CVC, PVV and EMV
• Implement and troubleshoot protocols and standards such as TR-31 and TR-34
• Investigate cryptographic and security incidents
• Perform security-focused code reviews and testing
• Work with clients and partners on technical integrations
• Participate in architecture, security and technical design discussions
• Research emerging cryptographic and security technologies
• Produce technical documentation for cryptographic systems and integrations

What you bring

• A Bachelor's degree in Computer Science, Computer Engineering, Electrical Engineering, Mathematics, Cybersecurity or a related field
• 5+ years of relevant professional experience, including production software development
• Strong foundations in computer science, cryptography and security
• Strong understanding of symmetric and asymmetric cryptography: AES, RSA, ECC, hashing, HMAC and key derivation
• Knowledge of cryptographic key management and lifecycle, secure random number generation and key material handling
• Knowledge of PKI, TLS and authentication
• Understanding of threat modelling, secure software development and common cryptographic implementation vulnerabilities
• Strong proficiency in at least one backend language: TypeScript/JavaScript, Java, Go, C/C++ or Python
• Ability to build and maintain REST APIs and service-to-service communication
• Proficiency with Linux, Git and modern software development practices
• Experience with automated testing, networking fundamentals and distributed systems
• Proficiency with observability, logging, metrics and tracing
• Knowledge of PCI PIN, PCI PTS and PCI DSS standards
• Knowledge of ISO 9564, ISO 8583 and ISO 20022 standards
• Knowledge of ANSI X9, EMV and PKCS standards
• Ability to work independently on technically complex problems
• Strong capability to explain complex cryptographic concepts clearly and work directly with technical client teams
• Ability to independently learn complex technical concepts and apply them practically

Nice to have

• Payment or fintech experience
• HSM experience and Thales payShield
• TR-31/TR-34 implementation or integration experience
• PKI and certificate infrastructure experience
• Cloud security experience
• Security research or R&D background
• Client-facing technical integrations experience
• Kubernetes and Docker containerisation experience
• CI/CD and Infrastructure as Code experience
• Cloud platforms and Linux administration
• Experience with Trusted Execution Environments (TEEs), Passkeys/WebAuthn, Zero-Knowledge Proofs, Fully Homomorphic Encryption, Confidential Computing or Post-Quantum Cryptography
• Hardware-backed security experience

About Araxi Group

Araxi Group specialises in cryptography and payment security solutions for financial systems.