Cryptography Engineer

As a Cryptography Engineer at Synthesis Software Technologies, you design, implement, and support secure cryptographic solutions for payment and financial services environments. You work at the intersection of applied cryptography, payment security, HSM integration, and backend engineering, tackling complex security challenges in production systems that protect millions of transactions.

What you'll do

• Design and develop cryptographic services and secure backend solutions
• Integrate applications with enterprise HSMs and cryptographic infrastructure
• Implement key management and key lifecycle processes
• Work with payment cryptography technologies including PIN Blocks, DUKPT, CVV/CVC, PVV, and EMV
• Implement and troubleshoot industry standards such as TR-31 and TR-34
• Investigate security and cryptographic incidents
• Conduct security-focused code reviews and testing
• Collaborate with clients and technical partners on integration projects
• Participate in architecture, security, and technical design discussions
• Research emerging cryptographic technologies and security innovations
• Create and maintain technical documentation and implementation guides

What you bring

• A Bachelor's degree in Computer Science, Computer Engineering, Electrical Engineering, Mathematics, Cybersecurity, or a related field
• 2+ years of professional experience in software engineering, cryptography, or security-related roles
• Experience building and supporting production systems
• Strong understanding of symmetric and asymmetric cryptography (AES, RSA, ECC), hashing, HMAC, key derivation, cryptographic key management and lifecycle processes, secure random number generation, PKI, TLS and authentication frameworks, and secure software development practices
• Knowledge of threat modelling and common implementation vulnerabilities and mitigation strategies
• Experience or knowledge of payment HSMs, TR-31 and TR-34, PIN block formats, DUKPT, CVV/CVC and PVV generation, EMV cryptography, payment key hierarchies, and key ceremonies
• Strong proficiency in one or more of TypeScript, JavaScript, Java, Go, C/C++, or Python
• Experience in backend application development, REST API design and integration, Linux environments, Git-based development workflows, automated testing, networking fundamentals, distributed systems, and observability including logging, metrics and tracing
• Ability to independently solve complex technical challenges

Nice to have

• Experience with Thales payShield HSMs
• Kubernetes, Docker and containerisation, CI/CD pipelines, Infrastructure as Code, cloud platforms and cloud security
• Linux administration, secrets management, and monitoring and observability tooling
• Exposure to standards such as PCI PIN, PCI PTS, PCI DSS, ISO 9564, ISO 8583, ISO 20022, ANSI X9, EMV Standards, and PKCS Standards
• Interest or experience in Trusted Execution Environments (TEEs), Passkeys and WebAuthn, Zero-Knowledge Proofs (ZKPs), Fully Homomorphic Encryption (FHE), Confidential Computing, Post-Quantum Cryptography, or Hardware-Backed Security

About Synthesis Software Technologies

Synthesis Software Technologies builds mission-critical payment and security systems, delivering secure cryptographic solutions for financial services environments. The company works at the forefront of applied cryptography and fintech security, solving highly complex technical challenges in production systems.