PostQuantumKryptographie

PostQuantumKry... is a field of cryptography focused on developing cryptographic systems that remain secure in the presence of quantum computers. It encompasses methods that would resist attacks based on quantum algorithms, notably Shor's algorithm, which can efficiently factor large integers and compute discrete logarithms. The field addresses the risk that widely used public-key schemes such as RSA and elliptic-curve cryptography could be rendered insecure once sufficiently powerful quantum hardware becomes available. Research aims to identify algorithms with known or believed quantum resistance and to establish practical deployment pathways.

Current post-quantum candidates fall into several families: lattice-based, code-based, multivariate, hash-based, and isogeny-based. Lattice-based schemes such as CRYSTALS-Kyber (for key encapsulation) and CRYSTALS-Dilithium (for digital signatures) have attracted significant attention. Code-based approaches include Classic McEliece. Hash-based signatures—for example SPHINCS+—offer strong security proofs with large key material. Multivariate-quadratic schemes and isogeny-based constructions provide alternative trade-offs in key size and computation. No single scheme is universally preferred; standardization bodies evaluate candidates for rules, performance, and implementation complexity, including resistance to cryptanalytic advances beyond quantum attacks.

Standardization and migration efforts, notably by national and international bodies, aim to integrate post-quantum algorithms into existing protocols such as TLS and PGP while maintaining interoperability with legacy systems. Hybrid approaches combine classical and post-quantum primitives to ease transition. Practical deployment considerations include key and signature sizes, computational load, memory usage, and hardware acceleration. As quantum computing progresses, organizations are encouraged to plan gradual upgrades and conduct threat assessments to balance security with cost and compatibility.