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2 commits

Author SHA1 Message Date
50b1e2e8ee Merge scalar into CurveField: one type universe, serial-only backend
Replicates dalek's gen merge: extract.sh co-extracts the Scalar52 backend
and scalar::from_bytes_mod_order[_wide] into the CurveField model (with this
fork's sub::black_box opaqued, its identity model ported to the merged
FunsExternal), pins RUSTFLAGS --cfg curve25519_dalek_backend="serial" so
the SIMD dispatch arm compiles out (get_selected_backend becomes a real
definition), and upgrades unwrap_u8 to the documented Choice-model
definition. ScalarDenote repoints by one import line; both buttons green
over the merged gen (scalar chain + field/group/dsm chain, all certificates
axiom-clean).

Prepares the verify-glue integration (CurveSig) on this fork.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-04 21:58:33 +02:00
6fe31be80d Add scalar-layer foundation (Scalar52 arithmetic mod ℓ)
Transpile the Scalar52 limb backend (backend::serial::u64::scalar
add/sub/mul/square/montgomery_*) from Rust to Lean via Charon/Aeneas,
scoped at the function level to the iterator-free arithmetic core.

  - verification/extract-scalar.sh: function-level Charon/Aeneas extraction.
    This fork (v4.1.3) inlines a local `black_box` (a volatile read used as an
    optimization barrier) inside Scalar52::sub; charon cannot translate the
    `&raw const` it lowers to, so it is marked --opaque and modeled below.
  - verification/gen/CurveScalar/{Types,Funs}.lean: transpiled model (27 defs)
  - verification/gen/CurveScalar/FunsExternal.lean: hand-written model of
    Scalar52::sub::black_box as the identity on u64 (a volatile read returns
    the value written; the qualifier is only an optimization barrier).
    TypesExternal.lean is decl-free — this fork pulls in no external types
    (unlike v5 dalek, which routes sub through subtle::Choice).
  - verification/Proofs/ScalarDenote.lean: semantic foundation — Scalar52
    denotation into ℤ/ℓℤ, limb-bound invariant, and L_val (the transpiled
    constants::L denotes exactly the group order ℓ, kernel-checked).
  - verification/check-scalar.sh: guarded compile of the gen modules plus the
    denotation foundation.

check-scalar.sh passes: gen compiles; denotation + L = ℓ proven.
add/sub/mul remain in progress.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-02 21:24:39 +02:00