PQShield is a post-quantum cryptography company founded in 2018 as a spin-out from the University of Oxford. Its headquarters are in Oxford, with offices in Paris, Amsterdam, New York, California and Tokyo. The company develops software and hardware cryptography designed to resist attacks from future quantum computers, including the PQMicroLib-Core and PQCryptoLib-Core software libraries, the PQCryptoLib-SDK for OpenSSL applications, the PQPlatform-CoPro secure coprocessor, the PQPlatform-TrustSys root-of-trust system, and the PQPerform hardware accelerators (Flare, Inferno and Flex).

PQShield's products serve the technology supply chain, including semiconductors and manufacturing, identity and payments, military and aerospace, system integrators, automotive, industrial IoT, network and telecommunications, and enterprise platforms. Reported customers and partners include AMD, Microchip Technologies, Collins Aerospace, Lattice Semiconductor, Sumitomo Electric, NTT Data and Mirise Technologies. The company has also worked with Bosch, and in 2024 it announced a collaboration with SiFive to integrate its coprocessor with RISC-V CPUs. In 2025 it signed a partnership with Telefonica Innovacion Digital and became a master government aggregator arrangement with Carahsoft for US public sector customers. In 2026 it was reported to have achieved NIST CAVP certification for PQMicroLib-Core and became an ST Authorized Partner.

PQShield's team includes cryptographers who contributed to the international NIST post-quantum cryptography standardization process. The company has received a FIPS 140-3 certification for its PQCryptoLib, has published over 100 research papers, and was named an IDC Innovator for Post-Quantum Cryptography in 2024. Its reported revenue rose sharply in 2025, according to recently published accounts.