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Digital Signatures for the Future: Dilithium, FALCON and SPHINCS+

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And so, our world of digital signatures revolves around RSA, ECDSA and EdDSA. We have long since dropped DSA, and only just approved EdDSA to be part of FIPS 186. But, all of these methods are under threat from quantum computers, and so we must bring in new methods which are quantum robust. The three methods that NIST has defined for standardization are:

  • CRYSTALS-Dilithium. Lattice-based. We have Dilithium2 (Level 1), Dilithium3 (Level 3), and Dilithium5 (Level 5). Level 1 is equivalent to 128-bit AES, Level 3 to 192-bit AES, and Level 5 to 256-bit AES.
  • Falcon. Lattice-based. We have Falcon-512 (Level 1) and Falcon-1024 (Level 5).
  • SPHINCS+. Hash-based. SPHINCS+-128 (Level 1), SPHINCS+-192 (Level 3), and SPHINCS+-256 (Level 5).

The following shows a sample run for timings with key generation, signing and verifying [here]:

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Prof Bill Buchanan OBE FRSE
ASecuritySite: When Bob Met Alice

Professor of Cryptography. Serial innovator. Believer in fairness, justice & freedom. Based in Edinburgh. Old World Breaker. New World Creator. Building trust.