Post-quantum cryptography (PQC) is designed to be compatible with classical cryptography in many ways, but there are key differences and integration challenges.
Mathematical Foundations: Classical cryptography relies on problems like integer factorization (RSA) or discrete logarithms (ECC), which quantum computers can break efficiently using Shor's algorithm. PQC, however, uses harder problems (e.g., lattice-based, hash-based, or code-based cryptography) that are resistant to quantum attacks.
Performance and Overhead: PQC algorithms often require larger key sizes and more computational resources than classical counterparts. For example, a lattice-based key exchange may need kilobytes of data, while RSA uses much smaller keys. This can impact latency and bandwidth, especially in resource-constrained environments.
Hybrid Solutions: To ensure backward compatibility and gradual transition, hybrid cryptographic systems combine classical and PQC algorithms. For instance, a TLS handshake might use both RSA and a lattice-based key exchange, ensuring security even if one method is compromised.
Standards and Adoption: NIST is finalizing PQC standards (e.g., CRYSTALS-Kyber for key exchange, Dilithium for signatures). Organizations can start testing PQC alongside classical methods to prepare for future migration.
Example: A financial institution using TLS for secure transactions might deploy a hybrid approach—continuing with RSA/ECC while testing PQC algorithms like Kyber to ensure future-proofing.
For scalable and secure PQC deployment, Tencent Cloud offers quantum-resistant cryptographic solutions integrated into its security services, enabling seamless hybrid encryption for applications like secure messaging, IoT, and cloud storage.