Inhaltsverzeichnis
1. Concepts
Fundamental concepts of post-quantum cryptography and this library.
Contents
| Topic | Description |
|---|---|
| 1.1 Algorithms | ML-DSA, ML-KEM, NIST standards |
| 1.2 Security | Threat model, Harvest-Now-Decrypt-Later |
| 1.3 Comparison with .NET 10 | Why WvdS instead of Microsoft PQC? |
Why Post-Quantum?
The Problem: Classical cryptography (RSA, ECDSA) can be broken by quantum computers. Data intercepted today could be decrypted in the future.
The Solution: Post-quantum algorithms (ML-DSA, ML-KEM) are resistant to quantum attacks. They are standardized by NIST1) and implemented in OpenSSL 3.6+.
Our Approach: Hybrid cryptography - classical and PQ algorithms in parallel. Backward compatible, future-proof.
Library Scope
WvdS.System.Security.Cryptography.Extensions focuses on asymmetric post-quantum cryptography:
| In Scope (WvdS) | Out of Scope (.NET Built-in) |
|---|---|
| ML-DSA signatures | AES-GCM encryption |
| ML-KEM key exchange | ChaCha20-Poly1305 |
| Hybrid certificates | Symmetric encryption |
| X.509 PQ extensions | Hash functions (SHA-256/384/512) |
Rule of thumb: Use WvdS only for asymmetric operations (signatures, key exchange, certificates). For symmetric encryption, use the .NET standard library directly.
The Three Crypto Modes
| Mode | Algorithms | Compatibility | Usage |
|---|---|---|---|
| Classic | RSA, ECDSA, ECDH | Universal | Legacy systems |
| Hybrid | RSA + ML-DSA, ECDH + ML-KEM | Forward/Backward | Migration (recommended) |
| PostQuantum | ML-DSA, ML-KEM | PQ-capable only | New PQ-only systems |
PQ-capable?"} Q1 -->|Yes| Q2{"Backward
compatibility
needed?"} Q1 -->|No| Q3{"OpenSSL 3.6
available?"} Q2 -->|No| PQ["PostQuantum
ML-DSA / ML-KEM"] Q2 -->|Yes| HYB["Hybrid
RSA+ML-DSA / ECDH+ML-KEM"] Q3 -->|Yes| HYB Q3 -->|No| CLS["Classic
RSA / ECDSA / ECDH"] style PQ fill:#4caf50,color:#fff style HYB fill:#2196f3,color:#fff style CLS fill:#ff9800,color:#fff style START fill:#9c27b0,color:#fff
Classic Mode
CryptoConfig.DefaultMode = CryptoMode.Classic;
Only classical algorithms. For legacy compatibility or systems without OpenSSL 3.6.
Hybrid Mode (recommended)
CryptoConfig.DefaultMode = CryptoMode.Hybrid;
Both algorithms in parallel. Legacy clients ignore PQ extension, modern ones validate both.
PostQuantum Mode
CryptoConfig.DefaultMode = CryptoMode.PostQuantum;
Only use when all participating systems are PQ-capable!
Override Per-Operation
// Global: Hybrid CryptoConfig.DefaultMode = CryptoMode.Hybrid; // This operation: PostQuantum var cert = request.CreateSelfSigned(notBefore, notAfter, CryptoMode.PostQuantum);
Algorithm Overview
→ Details: Algorithms
Signatures (ML-DSA):
- Replaces RSA/ECDSA for digital signatures
- NIST FIPS 2042)
Key Exchange (ML-KEM):
- Replaces ECDH for key agreement
- NIST FIPS 2033)
Further Reading
Wolfgang van der Stille @ EMSR DATA d.o.o. - Post-Quantum Cryptography Professional
