Post-Quantum

Post-Quantum is a UK-based cryptography vendor built around a bet made in 2009, years ahead of the market: that a sufficiently powerful quantum computer would eventually break the RSA and elliptic-curve cryptography underpinning most of the internet’s encryption, and that migrating to quantum-resistant algorithms would take enterprises and governments years to execute. The company builds quantum-safe encryption and identity products, including a hybrid post-quantum VPN and the Nomidio identity and authentication platform, combining classical and post-quantum algorithms so organizations can begin migration without waiting for a single cutover event.

The company’s post-quantum VPN protocol was standardized by the IETF in 2023, a notable validation for a small vendor in the cryptography space, and NATO’s Cyber Security unit has run trials of the technology — a bloc that treats “harvest now, decrypt later” data-interception risk as a near-term planning problem rather than a hypothetical one. Post-Quantum has focused its commercial push on financial services, national security, and critical-infrastructure customers, where long data-retention requirements make early migration to post-quantum cryptography (PQC) hard to postpone.

Post-Quantum’s most recent disclosed funding was a GBP 7 million Series A in 2016, well before NIST finalized its post-quantum cryptography standards in 2024. That gap, combined with a market now crowded with newer, better-capitalized PQC entrants, is the central open question about the business: technical credibility and standards-body validation are well established, but growth capital to compete at scale is less visible in public information.