(verify_accepts_iff_decompress, button-enforced)
Port of the dalek decompress chain to the risc0 fork (v4 gen):
- source patch 8b69091: decompress step_2 negate-then-conditional-assign
(the documented sqrt_ratio_i rewrite; sqrt_ratio_i itself was already
in the compatible shape); extract.sh: decompress un-opaqued,
re-extracted - the step_1/step_2 external axioms vanish from the
template, decompress is transparent.
- Proofs/DecompressSpec.lean: dalek port, instance rename
Shared0FieldElement51 -> SharedAFieldElement51.
- Proofs/FromBytesSpec.lean: PORT DELTA - this gen's from_bytes takes
RangeFrom subslices (bytes[k..]) into a local load8 CLOSURE with
literal indices instead of dalek's named load8_at: new
range_from_index_spec (over the step_simps-reduced slice index) +
closure_call_spec (same disjoint-OR loader math); window/telescope
arithmetic identical.
- Proofs/DecompressMain.lean: decompress_of_canonical (standard three)
+ verify_accepts_iff_decompress (corollary verbatim - this fork's
point-equation signature is byte-identical to dalek's):
accept <=> decompress(R) = [k]*(-A) + [s]*B (as points).
check.sh: 4-tier Phase 3b; full-lift cone exactly [3 standard +
Signature + sha512_hash3 + to_bytes + Error + Error.new]. Full button
green fresh.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Replicates dalek's apex with this fork's sha2-0.10 adaptation: the hash
oracle is the single monomorphic sha512_hash3(R, A, m) call (no foreign
types in its signature — the 0.10 Sha512 alias cannot be declared opaque),
and extraction runs --no-default-features so the error path avoids boxed
dyn-Error.
- gen/CurveSig: the extracted verify glue, definitionally welded to the
proven model (TypesExternal/FunsExternal import CurveField; every curve
and scalar call is a certified definition).
- Proofs/SigApexSpec.lean (unchanged from dalek): verify_loop_full (the
32-byte comparison = array equality; axiom cone exactly the standard
three) and verify_accepts_iff — accept IFF compress([s]B - [k]A) = R
byte-for-byte, SHA-512 opaque.
- check.sh Phase 3b: the apex axiom cone is enforced to be EXACTLY
[propext, Classical.choice, Quot.sound, ed25519.Signature,
verifying.sha512_hash3, ed25519.Signature.to_bytes,
signature.error.Error, signature.error.Error.new]
- zero curve, scalar, or backend axioms.
Full check.sh green: 17 standard certificates + the apex audit.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
