NIST picks Kyber, Dilithium, FALCON and SPHINCS+ for post-quantum crypto

The third round of the selection process of the NIST Post-Quantum Cryptography Standardization has concluded, and the third round report (NISTIR 8413) explains the choices. NIST’s announcement picks CRYSTALS-Kyber for general encryption and three schemes for digital signatures: CRYSTALS-Dilithium, FALCON and SPHINCS+. For signatures, NIST recommends CRYSTALS–Dilithium as the primary algorithm to be implemented. In addition, four of the alternate key-establishment candidate algorithms will advance to a fourth round of evaluation: BIKE, Classic McEliece, HQC, and SIKE. Bas Westerbaan at Cloudflare called the result a pleasant surprise, since NIST had said it would standardize only two signature schemes, and having Falcon next to Dilithium makes post-quantum authentication easier to deploy. NIST expects the standard to be finalized in about two years, which is a good window to find out where your RSA keys actually live.