Post-quantum signatures are digital signature schemes built to stay secure even if large quantum computers become practical. They are meant to replace or supplement today’s signature systems, such as RSA and elliptic-curve signatures, which could be weakened by quantum attacks.
In cyber security, signatures authenticate software updates, certificates, documents, and protocol messages. If a signature scheme fails, attackers may be able to impersonate trusted systems or forge code. Post-quantum signatures matter because defenders need long-term trust for data and infrastructure that must remain valid for years. In research and defense, they appear as candidates in standardization programs, benchmark targets for cryptanalysis, and migration planning for public-key infrastructure. Security teams evaluate them for key size, signature size, performance, and resistance to both classical and quantum attacks.