Sergiy User

I’m an Independent Cryptography Researcher focused on turning cutting-edge cryptographic ideas into practical, reliable systems. Constantly learning and keeping abreast with the latest developments is how I work, from first principles to implementation details.

In my self-employed research work, I concentrate on post-quantum cryptography, homomorphic computations (FHE), and interactive and non-interactive zero-knowledge proofs. I also explore distributed algorithms and number theory to connect cryptographic guarantees with real-world performance and scalability.

Before fully focusing on research, I served as a VP of Software Engineering and led engineering teams through complex technical programs. I combined technical architecture and engineering management with hands-on execution—spanning cryptography and blockchain architecture, smart contracts, distributed systems, and continuous improvement through CI, debugging, and code review.

I’ve also led product and engineering efforts across roles like Team Lead, Lead Engineer, and Software Developer, strengthening my approach to mentoring, coaching, and technical leadership. I thrive in environments that value collaboration, clear communication, and disciplined engineering documentation.