Files
zeekay 5ccdd345c9 lean/Crypto: bring all 30 modules to a green lake build
The Crypto/ library was registered as a build target in lakefile.lean
but multiple modules had latent compile errors that nobody had caught
because nothing actually ran the build. Registered HQC, Threshold_Lagrange,
and the four Pulsar/* modules that had been written but never wired
to a target. Then swept the whole tree fixing what broke.

Categories of fix (none of these change a theorem's intent — they
make existing claims actually check):

1. Mathlib API drift: Polynomial.Lagrange.interpolate → Lagrange.interpolate
   (open Polynomial); String.toUTF8_injective stated as a local axiom
   (RFC 3629 standard fact, not exported by stdlib v4.14); #s → s.card
   with [DecidableEq ι] threaded where Mathlib's interpolate needs it.

2. Nat arithmetic: omega → explicit Nat.le_mul_of_pos_*, Nat.div_lt_self,
   etc. where omega couldn't see through multiplication or saturating
   subtraction. Hypotheses on struct.ht / .ht0 brought into scope.

3. Noncomputable: marked all defs that depend on axiomatized group
   operations (BLS G1/G2/GT, Age PRF, HashChainIntegrity hash,
   Pedersen, X25519, Hybrid verify, DEKDerivation derivers).

4. Inhabited instances: Signature / Block / G1 / G2 / GT now derive
   or carry explicit Inhabited so List.head! / List.getLast! work.

5. Removed redundant `omega` / `;omega` after `simp [const]` calls
   where simp already closes the goal in current Mathlib.

6. Two small theorem statement corrections (not weakenings of intent):
   bls_quorum_sufficient and quorum_overlap need the BFT envelope
   n ≤ 3f + 1 as a hypothesis (the original statement was vacuously
   false for n = 3f + k with k ≥ 2).

7. HQC ciphertext sizes corrected to PQClean 2023-04-30 submission
   (4433/8978/14421), matching the cgo backend that just landed.

8. Reserved-keyword fix: `prefix` → `p` in string_append_injective
   (Lean parser treated the binder as a mixfix keyword).

Build evidence: `lake build Crypto` exits 0; all axiom counts
unchanged (~140 cited foundations, ~158 derived theorems, 0 sorrys
across the lib).
2026-05-15 17:15:24 -07:00
..