crypto Namespace Reference

Classes
class	FieldSponge
	Implements a cryptographic sponge over prime fields. Implements the sponge specification from the Community Cryptographic Specification Project see https://github.com/C2SP/C2SP/blob/792c1254124f625d459bfe34417e8f6bdd02eb28/poseidon-sponge.md (Note: this spec was not accepted into the C2SP repo, we might want to reference something else!) More...
class	generator_data
	class that stores precomputed generators used for Pedersen commitments and Pedersen hashes More...
struct	GeneratorContext
class	pedersen_commitment_base
	Performs pedersen commitments! More...
class	pedersen_hash_base
	Performs pedersen hashes! More...
class	Poseidon2
struct	Poseidon2Bn254ScalarFieldParams
class	Poseidon2Permutation
	Applies the Poseidon2 permutation function from https://eprint.iacr.org/2023/323 . This algorithm was implemented using https://github.com/HorizenLabs/poseidon2 as a reference. More...

Typedefs
using	pedersen_commitment = pedersen_commitment_base< curve::Grumpkin >
using	pedersen_hash = pedersen_hash_base< curve::Grumpkin >

Functions
template<typename Hash , typename MessageContainer , typename KeyContainer >
std::array< uint8_t, Hash::OUTPUT_SIZE >	hmac (const MessageContainer &message, const KeyContainer &key)
	Compute an HMAC given a secret key and a message.
template<typename Hash , typename Fr , typename MessageContainer , typename KeyContainer > requires (Hash::OUTPUT_SIZE == 32)
Fr	get_unbiased_field_from_hmac (const MessageContainer &message, const KeyContainer &key)
	Takes a size-HASH_OUTPUT buffer from HMAC and converts into a field element.
	TEST (Pedersen, Commitment)
	TEST (Pedersen, CommitmentWithZero)
	TEST (Pedersen, CommitmentProf)
	TEST (Pedersen, GeneratorPrinter)
	TEST (Pedersen, Hash)
	TEST (Pedersen, HashWithIndex)

Detailed Description

AES-128 Cipher

Implements AES-128 block cipher, and buffer encryption using cbc cipher chaining

Based off of tiny-AES by @kokke : https://github.com/kokke/tiny-AES-c

Function Documentation

get_unbiased_field_from_hmac()

template<typename Hash , typename Fr , typename MessageContainer , typename KeyContainer >
requires (Hash::OUTPUT_SIZE == 32)

Fr crypto::get_unbiased_field_from_hmac	(	const MessageContainer &	message,
		const KeyContainer &	key
	)

Takes a size-HASH_OUTPUT buffer from HMAC and converts into a field element.

We assume HASH_OUTPUT = 32. Reducing HMAC(key, message) modulo r would result in an unacceptable bias. We hash input with 0 and 1 to produce 64 bytes of input data. This is then converted into a uin512_t, which is taken modulo Fr::modulus to produce our field element, where the statistical bias is negligble in the security parameter.

Template Parameters

Hash	the hash function we're using
Fr	field type
MessageContainer	a byte container (std::vector<uint8_t>, std::array<uint8_t, ...>, std::string)
KeyContainer	a byte container

Parameters

message	the input buffer
key	key used to derive

Returns

Fr output field element as uint512_t( H(10...0 || HMAC(k,m)) || H(00...0 || HMAC(k,m)) ) % r

hmac()

template<typename Hash , typename MessageContainer , typename KeyContainer >

std::array< uint8_t, Hash::OUTPUT_SIZE > crypto::hmac	(	const MessageContainer &	message,
		const KeyContainer &	key
	)

Compute an HMAC given a secret key and a message.

Template Parameters

Hash	hasher being used
MessageContainer	a byte container (std::vector<uint8_t>, std::array<uint8_t, ...>, std::string)
KeyContainer	a byte container

Parameters

message	the message!
key	the key!

Returns

std::array<uint8_t, Hash::OUTPUT_SIZE> the HMAC output!