(also quantum-proof cryptography, quantum-safe cryptography, quantum-resistant cryptography)
A cryptography discipline dealing with algorithms that are believed to be protected against attacks from powerful quantum computers. Post-quantum cryptography is a preventive effort to maintain cybersecurity in the future, as the currently available quantum technology still lacks the processing power to break existing secure algorithms.
Quantum computing poses the biggest threat to modern public key cryptography. Sufficiently advanced quantum computers can easily break the three problems forming the foundation of most public key algorithms: the integer factorization problem, the discrete logarithm problem, and the elliptic-curve discrete logarithm problem. By contrast, symmetric cryptography is believed to be much harder for quantum computer attacks to penetrate.