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Docstring wrap

This commit is contained in:
Deirdre Connolly 2020-07-29 02:35:46 -04:00 committed by Deirdre Connolly
parent e22afa3c8f
commit 1d494a2b7a
1 changed files with 23 additions and 27 deletions
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50
zebra-chain/src/commitments/sapling.rs
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@ -19,11 +19,10 @@ use crate::{
/// Generates a random scalar from the scalar field \mathbb{F}_r_𝕁.
///
/// The prime order subgroup 𝕁^(r) is the order-r_𝕁 subgroup of 𝕁
/// after the Edwards cofactor h_𝕁 = 8 is factored out. This function
/// is useful when generating the uniform distribution on
/// \mathbb{F}_r_𝕁 needed for Sapling commitment schemes' trapdoor
/// generators.
/// The prime order subgroup 𝕁^(r) is the order-r_𝕁 subgroup of 𝕁 after the
/// Edwards cofactor h_𝕁 = 8 is factored out. This function is useful when
/// generating the uniform distribution on \mathbb{F}_r_𝕁 needed for Sapling
/// commitment schemes' trapdoor generators.
///
/// https://zips.z.cash/protocol/protocol.pdf#jubjub
pub fn generate_trapdoor<T>(csprng: &mut T) -> jubjub::Fr
@ -36,14 +35,14 @@ where
jubjub::Fr::from_bytes_wide(&bytes)
}
/// "...an algebraic hash function with collision resistance (for
/// fixed input length) derived from assumed hardness of the Discrete
/// Logarithm Problem on the Jubjub curve."
/// "...an algebraic hash function with collision resistance (for fixed input
/// length) derived from assumed hardness of the Discrete Logarithm Problem on
/// the Jubjub curve."
///
/// PedersenHash is used in the definitions of Pedersen commitments (§
/// 5.4.7.2‘Windowed Pedersen commitments’), and of the Pedersen hash
/// for the Sapling incremental Merkle tree (§
/// 5.4.1.3 ‘MerkleCRH^Sapling Hash Function’).
/// 5.4.7.2‘Windowed Pedersen commitments’), and of the Pedersen hash for the
/// Sapling incremental Merkle tree (§ 5.4.1.3 ‘MerkleCRH^Sapling Hash
/// Function’).
///
/// https://zips.z.cash/protocol/protocol.pdf#concretepedersenhash
#[allow(non_snake_case)]
@ -72,8 +71,8 @@ pub fn pedersen_hash_to_point(domain: [u8; 8], M: &BitVec<Lsb0, u8>) -> jubjub::
let mut result = jubjub::ExtendedPoint::identity();
// Split M into n segments of 3 * c bits, where c = 63, padding
// the last segment with zeros.
// Split M into n segments of 3 * c bits, where c = 63, padding the last
// segment with zeros.
//
// https://zips.z.cash/protocol/protocol.pdf#concretepedersenhash
for (i, segment) in M.chunks(189).enumerate() {
@ -85,9 +84,9 @@ pub fn pedersen_hash_to_point(domain: [u8; 8], M: &BitVec<Lsb0, u8>) -> jubjub::
/// Mixing Pedersen Hash Function
///
/// Used to compute ρ from a note commitment and its position in the
/// note commitment tree. It takes as input a Pedersen commitment P,
/// and hashes it with another input x.
/// Used to compute ρ from a note commitment and its position in the note
/// commitment tree. It takes as input a Pedersen commitment P, and hashes it
/// with another input x.
///
/// MixingPedersenHash(P, x) := P + [x]FindGroupHash^J^(r)(“Zcash_J_”, “”)
///
@ -99,9 +98,8 @@ pub fn mixing_pedersen_hash(P: jubjub::ExtendedPoint, x: jubjub::Fr) -> jubjub::
P + find_group_hash(J, b"") * x
}
/// Construct a 'windowed' Pedersen commitment by reusing a Perderson
/// hash constructon, and adding a randomized point on the Jubjub
/// curve.
/// Construct a 'windowed' Pedersen commitment by reusing a Perderson hash
/// constructon, and adding a randomized point on the Jubjub curve.
///
/// WindowedPedersenCommit_r (s) := \
/// PedersenHashToPoint(“Zcash_PH”, s) + [r]FindGroupHash^J^(r)(“Zcash_PH”, “r”)
@ -166,14 +164,12 @@ impl ZcashDeserialize for NoteCommitment {
}
impl NoteCommitment {
/// Generate a new _NoteCommitment_ and the randomness used to
/// create it.
/// Generate a new _NoteCommitment_ and the randomness used to create it.
///
/// We return the randomness because it is needed to construct a
/// _Note_, before it is encrypted as part of an _Output
/// Description_.
/// We return the randomness because it is needed to construct a _Note_,
/// before it is encrypted as part of an _Output Description_.
///
/// NoteCommit^Sapling_rcm (g*_d , pk*_d , v) := \
/// NoteCommit^Sapling_rcm (g*_d , pk*_d , v) :=
/// WindowedPedersenCommit_rcm([1; 6] || I2LEBSP_64(v) || g*_d || pk*_d)
///
/// https://zips.z.cash/protocol/protocol.pdf#concretewindowedcommit
@ -219,8 +215,8 @@ impl NoteCommitment {
}
}
/// A Homomorphic Pedersen commitment to the value of a note, used in
/// Spend and Output Descriptions.
/// A Homomorphic Pedersen commitment to the value of a note, used in Spend and
/// Output Descriptions.
///
/// https://zips.z.cash/protocol/protocol.pdf#concretehomomorphiccommit
#[derive(Clone, Deserialize, PartialEq, Serialize)]