README
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Hashing to Elliptic Curves
IETF Data Tracker: draft-irtf-cfrg-hash-to-curve
Internet-Draft: git repository
This document specifies a number of algorithms that may be used to encode or hash an arbitrary string to a point on an elliptic curve.
Reference Implementation
The purpose of this implementation is for generating test vectors and enabling cross compatibility with other implementations.
This implementation is for reference only. It MUST NOT be used in production systems.
Development branch: master
Draft versions implemented
Latest: v14
Previous: v12, v10, v08, v07, v06, v05.
Compatible Implementations
Internals
Contact
Feel free to open a github issue for anything related to the implementation, otherwise e-mail authors of the draft.
Documentation
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Overview ¶
Package h2c provides implementations of hashing functions that take arbitrary-length byte strings and output a point on an elliptic curve.
These methods follow the current work-in-progress standardization effort at IETF https://datatracker.ietf.org/doc/draft-irtf-cfrg-hash-to-curve.
Version: draft-irtf-cfrg-hash-to-curve-14
Index ¶
Constants ¶
const MaxDSTLength = 255
MaxDSTLength is the maximum allowed length for domain separatio tags.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Expander ¶
type Expander interface {
Expand(in []byte, len uint) (pseudo []byte)
// contains filtered or unexported methods
}
Expander allows to generate a pseudo-random byte string of a determined length.
type ExpanderDesc ¶
type ExpanderDesc struct {
Type ExpanderType
ID uint // This id is converted to either crypto.Hash or to xof.Xof
}
ExpanderDesc describes an expander
type ExpanderType ¶
type ExpanderType uint
ExpanderType identifies the type of expander function.
const ( // XMD denotes an expander based on a Merkle-Damgard hash function. XMD ExpanderType = iota // XOF denotes an expander based on an extendable output function. XOF // OTHER is reserved for a user-designed expander function (not implemented). OTHER )
type HashToPoint ¶
type HashToPoint interface {
// IsRandomOracle returns true if the output distribution is
// indifferentiable from a random oracle.
IsRandomOracle() bool
// Hash returns a point on an elliptic curve given a byte string.
Hash(in []byte) C.Point
// GetCurve returns the destination elliptic curve.
GetCurve() C.EllCurve
// GetHashToScalar returns a hash function that hashes strings to field elements.
GetHashToScalar() HashToScalar
}
HashToPoint represents a complete and secure function for hashing strings to points.
type HashToScalar ¶
type HashToScalar interface {
// GetScalarField returns the field of scalars.
GetScalarField() GF.Field
// Hash returns an element of a field given a byte string.
Hash(in []byte) GF.Elt
}
HashToScalar allows to hash string into the field of scalars used for scalar multiplication.
type SuiteID ¶
type SuiteID string
SuiteID is the identifier of supported hash to curve suites.
const ( P256_XMDSHA256_SSWU_NU_ SuiteID = "P256_XMD:SHA-256_SSWU_NU_" P256_XMDSHA256_SSWU_RO_ SuiteID = "P256_XMD:SHA-256_SSWU_RO_" P384_XMDSHA384_SSWU_NU_ SuiteID = "P384_XMD:SHA-384_SSWU_NU_" P384_XMDSHA384_SSWU_RO_ SuiteID = "P384_XMD:SHA-384_SSWU_RO_" P521_XMDSHA512_SSWU_NU_ SuiteID = "P521_XMD:SHA-512_SSWU_NU_" P521_XMDSHA512_SSWU_RO_ SuiteID = "P521_XMD:SHA-512_SSWU_RO_" Curve25519_XMDSHA512_ELL2_NU_ SuiteID = "curve25519_XMD:SHA-512_ELL2_NU_" Curve25519_XMDSHA512_ELL2_RO_ SuiteID = "curve25519_XMD:SHA-512_ELL2_RO_" Edwards25519_XMDSHA512_ELL2_NU_ SuiteID = "edwards25519_XMD:SHA-512_ELL2_NU_" Edwards25519_XMDSHA512_ELL2_RO_ SuiteID = "edwards25519_XMD:SHA-512_ELL2_RO_" Curve448_XOFSHAKE256_ELL2_NU_ SuiteID = "curve448_XOF:SHAKE256_ELL2_NU_" Curve448_XOFSHAKE256_ELL2_RO_ SuiteID = "curve448_XOF:SHAKE256_ELL2_RO_" Edwards448_XOFSHAKE256_ELL2_NU_ SuiteID = "edwards448_XOF:SHAKE256_ELL2_NU_" Edwards448_XOFSHAKE256_ELL2_RO_ SuiteID = "edwards448_XOF:SHAKE256_ELL2_RO_" Secp256k1_XMDSHA256_SSWU_NU_ SuiteID = "secp256k1_XMD:SHA-256_SSWU_NU_" Secp256k1_XMDSHA256_SSWU_RO_ SuiteID = "secp256k1_XMD:SHA-256_SSWU_RO_" BLS12381G1_XMDSHA256_SSWU_NU_ SuiteID = "BLS12381G1_XMD:SHA-256_SSWU_NU_" BLS12381G1_XMDSHA256_SSWU_RO_ SuiteID = "BLS12381G1_XMD:SHA-256_SSWU_RO_" BLS12381G2_XMDSHA256_SSWU_NU_ SuiteID = "BLS12381G2_XMD:SHA-256_SSWU_NU_" BLS12381G2_XMDSHA256_SSWU_RO_ SuiteID = "BLS12381G2_XMD:SHA-256_SSWU_RO_" )
Source Files
Directories
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| Path | Synopsis |
|---|---|
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Package mapping contains a set of functions to construct functions that take a field element and return a point on an elliptic curve.
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Package mapping contains a set of functions to construct functions that take a field element and return a point on an elliptic curve. |