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Exhibit 13 of 23
Hall 4 · Exhibit 2 1 min

The Five Families of PQC

Diversification as a defense strategy

Why fiveDiversify so one break ≠ total collapse
LatticeML-KEM · ML-DSA (the workhorses)
Hash / CodeSLH-DSA · HQC · McEliece (backups)
IsogenySIKE — broken 2022 (cautionary tale)
Try it yourself
PQC Toolkit
Filterable algorithm cards for every PQC family.

NIST deliberately standardized algorithms from multiple mathematical families so that a breakthrough against one does not compromise the entire ecosystem. For twenty years, the internet relied on a single mathematical basket. Cryptographers building recognized they could not repeat that mistake.

FamilyAlgorithmFIPSJobStatus
LatticeML-KEM (Kyber)FIPS 203Key Exchange (KEM)Chrome/Cloudflare live; Apple PQ3; Signal
LatticeML-DSA (Dilithium)FIPS 204Digital SignaturesOpenSSL/BoringSSL; CNSA 2.0
HashSLH-DSA (SPHINCS+)FIPS 205Signatures (backup)Standardized; backup if lattice breaks
CodeHQCPendingKEM (non-lattice backup)Selected Mar 2025; Meta co-authored
CodeClassic McElieceUnder eval.Static KEM1+ MB keys; high-security static use
IsogenySIKE (broken)NoneN/ABroken 2022 on desktop in ~1 hour

Key Takeaways

  • NIST standardized algorithms from multiple math families so a breakthrough against one doesn't compromise all
  • Lattice-based (ML-KEM, ML-DSA), hash-based (SLH-DSA), and code-based (HQC) are the primary families
  • SIKE (isogeny-based) was broken in 2022, proving diversification is essential