Post-quantum cryptography (PQC) develops algorithms resistant to quantum computer attacks. NIST standardized CRYSTALS-Kyber (key encapsulation) and CRYSTALS-Dilithium (signatures) in 2024.
Quantum computers will break RSA and ECC via Shor's algorithm. "Harvest now, decrypt later" attacks store encrypted traffic to decrypt once quantum computers exist. Begin crypto-agile migration planning now.