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Update comments on `gadget::note_commit`

This commit is contained in:
Jack Grigg 2022-05-04 02:59:22 +00:00
parent 903f9e8160
commit b46e4822d2
1 changed files with 15 additions and 6 deletions
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21
src/circuit/note_commit.rs
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@ -1647,6 +1647,11 @@ pub(in crate::circuit) mod gadgets {
d_1,
)?;
// cm = NoteCommit^Orchard_rcm(g★_d || pk★_d || i2lebsp_{64}(v) || rho || psi)
//
// `cm = ⊥` is handled internally to `CommitDomain::commit`: incomplete addition
// constraints allows ⊥ to occur, and then during synthesis it detects these edge
// cases and raises an error (aborting proof creation).
let (cm, zs) = {
let message = Message::from_pieces(
chip.clone(),
@ -1669,6 +1674,8 @@ pub(in crate::circuit) mod gadgets {
)?
};
// `CommitDomain::commit` returns the running sum for each `MessagePiece`. Grab
// the outputs that we will need for canonicity checks.
let z13_a = zs[0][13].clone();
let z13_c = zs[2][13].clone();
let z1_d = zs[3][1].clone();
@ -1677,6 +1684,7 @@ pub(in crate::circuit) mod gadgets {
let g_2 = z1_g.clone();
let z13_g = zs[6][13].clone();
// Witness and constrain the bounds we need to ensure canonicity.
let (a_prime, z13_a_prime) = canon_bitshift_130(
&lookup_config,
layouter.namespace(|| "x(g_d) canonicity"),
@ -1704,6 +1712,7 @@ pub(in crate::circuit) mod gadgets {
g_2,
)?;
// Finally, assign values to all of the NoteCommit regions.
let cfg = note_commit_chip.config;
let b_1 = cfg
@ -1764,7 +1773,7 @@ pub(in crate::circuit) mod gadgets {
Ok(cm)
}
// A canonicity check helper used in checking x(g_d), y(g_d), and y(pk_d).
/// A canonicity check helper used in checking x(g_d), y(g_d), and y(pk_d).
fn canon_bitshift_130(
lookup_config: &LookupRangeCheckConfig<pallas::Base, 10>,
mut layouter: impl Layouter<pallas::Base>,
@ -1796,7 +1805,7 @@ pub(in crate::circuit) mod gadgets {
Ok((a_prime, zs[13].clone()))
}
// Check canonicity of `x(pk_d)` encoding
/// Check canonicity of `x(pk_d)` encoding.
fn pkd_x_canonicity(
lookup_config: &LookupRangeCheckConfig<pallas::Base, 10>,
mut layouter: impl Layouter<pallas::Base>,
@ -1835,7 +1844,7 @@ pub(in crate::circuit) mod gadgets {
Ok((b3_c_prime, zs[14].clone()))
}
// Check canonicity of `rho` encoding
/// Check canonicity of `rho` encoding.
fn rho_canonicity(
lookup_config: &LookupRangeCheckConfig<pallas::Base, 10>,
mut layouter: impl Layouter<pallas::Base>,
@ -1874,7 +1883,7 @@ pub(in crate::circuit) mod gadgets {
Ok((e1_f_prime, zs[14].clone()))
}
// Check canonicity of `psi` encoding
/// Check canonicity of `psi` encoding.
fn psi_canonicity(
lookup_config: &LookupRangeCheckConfig<pallas::Base, 10>,
mut layouter: impl Layouter<pallas::Base>,
@ -1911,8 +1920,8 @@ pub(in crate::circuit) mod gadgets {
Ok((g1_g2_prime, zs[13].clone()))
}
// Check canonicity of y-coordinate given its LSB as a value.
// Also, witness the LSB and return the witnessed cell.
/// Check canonicity of y-coordinate given its LSB as a value.
/// Also, witness the LSB and return the witnessed cell.
fn y_canonicity(
lookup_config: &LookupRangeCheckConfig<pallas::Base, 10>,
y_canon: &YCanonicity,