tz

Documentation

Overview

Package tz contains Tillich-Zémor checksum implementations using different backends.

Copyright 2022 (c) NSPCC

Index

• Constants
• func Concat(hs [][]byte) ([]byte, error)
• func New() hash.Hash
• func SubtractL(c, a []byte) (b []byte, err error)
• func SubtractR(c, b []byte) (a []byte, err error)
• func Sum(data []byte) [Size]byte
• func Validate(h []byte, hs [][]byte) (bool, error)
• type GF127

Constants

const (
	// Size is the size of a Tillich-Zémor hash sum in bytes.
	Size = 64
)

Functions

func Concat

func Concat(hs [][]byte) ([]byte, error)

Concat performs combining of hashes based on homomorphic property.

func New

func New() hash.Hash

New returns a new hash.Hash computing the Tillich-Zémor checksum. The Hash also implements encoding.BinaryMarshaler and encoding.BinaryUnmarshaler to marshal and unmarshal the internal state of the hash.

func SubtractL

func SubtractL(c, a []byte) (b []byte, err error)

SubtractL returns hash b, such that Concat(a, b) == c This is possible, because Tillich-Zémor hash is actually a matrix which can be inversed.

func SubtractR

func SubtractR(c, b []byte) (a []byte, err error)

SubtractR returns hash a, such that Concat(a, b) == c This is possible, because Tillich-Zémor hash is actually a matrix which can be inversed.

func Sum

func Sum(data []byte) [Size]byte

Sum returns Tillich-Zémor checksum of data.

func Validate

func Validate(h []byte, hs [][]byte) (bool, error)

Validate checks if hashes in hs combined are equal to h.

Types

type GF127

type GF127 = gf127.GF127