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Merged
notnotraju merged 10 commits into from
Mar 4, 2026
Merged

chore: unify splitting scalars interface #20805

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6fb3dea
added tests showing edge-case failure for splitting_scalars and EC sc…
Feb 18, 2026
ce106a2
fixed the splitting scalars issue, modified the python documentation …
Feb 19, 2026
b186963
Merge branch 'merge-train/barretenberg' of github.com:AztecProtocol/a…
Feb 19, 2026
188e092
added biggroup_goblin regression test
Feb 20, 2026
2042e84
refactored the literate python program, added information about fq an…
Feb 23, 2026
f9be7ca
unified interfaces for BN fields and secp256k1, removed the "384-bit"…
Feb 24, 2026
6aefc41
fix the WASM issue by restructuring the `reduce_once()` calls.
Feb 24, 2026
0ae3cc1
updated the documentation to clarify when/how secp256k1 split scalars…
Feb 27, 2026
d37aa1c
Merge remote-tracking branch 'origin/merge-train/barretenberg' into r…
Feb 27, 2026
1784aa6
updated endomorphism scalars documentation to explain why the short b…
Mar 4, 2026
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17 changes: 8 additions & 9 deletions barretenberg/cpp/src/barretenberg/ecc/curves/secp256k1/secp256k1.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -217,15 +217,14 @@ struct FrParams {
static constexpr uint64_t endo_b2_lo = 0xe86c90e49284eb15ULL;
static constexpr uint64_t endo_b2_mid = 0x3086d221a7d46bcdULL;

static constexpr uint64_t endo_g1_lo = 0xE893209A45DBB031ULL;
static constexpr uint64_t endo_g1_mid = 0x3DAA8A1471E8CA7FULL;
static constexpr uint64_t endo_g1_hi = 0xE86C90E49284EB15ULL;
static constexpr uint64_t endo_g1_hihi = 0x3086D221A7D46BCDULL;

static constexpr uint64_t endo_g2_lo = 0x1571B4AE8AC47F71ULL;
static constexpr uint64_t endo_g2_mid = 0x221208AC9DF506C6ULL;
static constexpr uint64_t endo_g2_hi = 0x6F547FA90ABFE4C4ULL;
static constexpr uint64_t endo_g2_hihi = 0xE4437ED6010E8828ULL;
// 256-bit-shift constants: g1 = floor((-b1) * 2^256 / r), g2 = floor(b2 * 2^256 / r)
// See endomorphism_scalars.py compute_splitting_constants() for derivation.
static constexpr uint64_t endo_g1_lo = 0x6F547FA90ABFE4C4ULL;
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@notnotraju notnotraju Feb 24, 2026

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need new constants here

static constexpr uint64_t endo_g1_mid = 0xE4437ED6010E8828ULL;
static constexpr uint64_t endo_g1_hi = 0x0ULL;

static constexpr uint64_t endo_g2_lo = 0xE86C90E49284EB15ULL;
static constexpr uint64_t endo_g2_mid = 0x3086D221A7D46BCDULL;

// Not used in secp256k1
static constexpr uint64_t primitive_root_0 = 0UL;
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6 changes: 1 addition & 5 deletions barretenberg/cpp/src/barretenberg/ecc/curves/secp256k1/secp256k1_endo_notes.hpp
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Expand Up @@ -14,11 +14,9 @@ struct basis_vectors {
uint64_t endo_g1_lo = 0;
uint64_t endo_g1_mid = 0;
uint64_t endo_g1_hi = 0;
uint64_t endo_g1_hihi = 0;
uint64_t endo_g2_lo = 0;
uint64_t endo_g2_mid = 0;
uint64_t endo_g2_hi = 0;
uint64_t endo_g2_hihi = 0;
uint64_t endo_minus_b1_lo = 0;
uint64_t endo_minus_b1_mid = 0;
uint64_t endo_b2_lo = 0;
Expand Down Expand Up @@ -108,19 +106,17 @@ struct basis_vectors {
}

uint512_t minus_b1 = -b1;
uint512_t shift256 = uint512_t(1) << 384;
uint512_t shift256 = uint512_t(1) << 256;
uint512_t g1 = (-b1 * shift256) / uint512_t(secp256k1::fr::modulus);
uint512_t g2 = (b2 * shift256) / uint512_t(secp256k1::fr::modulus);

basis_vectors result;
result.endo_g1_lo = g1.lo.data[0];
result.endo_g1_mid = g1.lo.data[1];
result.endo_g1_hi = g1.lo.data[2];
result.endo_g1_hihi = g1.lo.data[3];
result.endo_g2_lo = g2.lo.data[0];
result.endo_g2_mid = g2.lo.data[1];
result.endo_g2_hi = g2.lo.data[2];
result.endo_g2_hihi = g2.lo.data[3];
result.endo_minus_b1_lo = minus_b1.lo.data[0];
result.endo_minus_b1_mid = minus_b1.lo.data[1];
result.endo_b2_lo = b2.lo.data[0];
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