RSA vs ECC vs Post-Quantum (CRYSTALS-Kyber) vs QKD
Cryptography Comparison
Comparison of 4 cryptographic approaches — key size, performance, quantum resistance, and standardization status.
RSA-2048ECC P-256Kyber-768QKD (BB84)
Full Specification Comparison
| Specification | RSA-2048 | ECC P-256 | Kyber-768 | QKD (BB84) |
|---|---|---|---|---|
| Quantum Resistant | No | No | Yes | Yes |
| Key Size | 2048-bit | 256-bit | 1568-bit | N/A (physical) |
| Performance | Slow | Fast | Moderate | Slow (hardware) |
| Standardized | Yes (PKCS#1) | Yes (FIPS 186) | Yes (FIPS 203) | Yes (ETSI/ITU) |
| Infrastructure | Universal | Universal | Emerging | Specialized fiber |
| Key Distribution | Math-based | Math-based | Math-based | Physics-based |
| Migration Urgency | High (retire) | High (retire) | Recommended | Long-term |
Expert Verdict
RSA and ECC are vulnerable to quantum attacks; Kyber is the NIST-selected PQC standard; QKD offers physics-based security but requires specialized hardware.
Subject Breakdown
RSA-2048
0 Category Wins
ECC P-256
0 Category Wins
Kyber-768
1 Category Wins
- ★ Quantum Resistant: Yes
QKD (BB84)
1 Category Wins
- ★ Key Distribution: Physics-based