DEV Community

H33.ai
H33.ai

Posted on • Originally published at h33.ai

74 Bytes: How We Fit Three Post-Quantum Signature Families Into a Bitcoin OP_RETURN

The Size Problem

Post-quantum signatures are massive. Dilithium: 2,420 bytes. FALCON: 666 bytes. SPHINCS+: 7,856 bytes. Combined: 10,942 bytes. Bitcoin OP_RETURN limit: 80 bytes.

You cannot fit even one PQ signature in a Bitcoin transaction, let alone three.

Distillation, Not Compression

H33-74 does not compress signatures. Compression implies reversibility. H33-74 distills three post-quantum signature families into a fixed 74 bytes — the same 74 bytes regardless of key size, data size, or which PQ family is used.

The construction is:

  • 32 bytes on-chain (fits in OP_RETURN)
  • 42 bytes in Cachee (H33 cache layer)
  • 74 bytes total. Forever. Any computation.

Three independent mathematical hardness assumptions: MLWE lattices (Dilithium/ML-DSA), NTRU lattices (FALCON), and stateless hash functions (SPHINCS+/SLH-DSA). An attacker must break all three simultaneously.

No Fork Required

H33-74 drops into existing Bitcoin UTXOs. No consensus changes. No soft fork. No hard fork. The signature attestation rides in OP_RETURN — a field Bitcoin already supports.

118 tests passing. Live on Bitcoin mainnet.

Whitepaper: h33.ai/substrate/whitepaper

Patent filed.


Introducing H33-74. 74 bytes. Any computation. Post-quantum attested. Forever.

Top comments (0)