ChargeHash

Table of Contents

• Introduction
• Author
• License
• Implementation

Introduction

ChargeHash is the efficient non-cryptographic hash function (for hashing variable-length byte arrays to fixed-length outputs) that has endian-independent byte copying (by default), excellent non-cryptographic output quality (passes SMHasher3 --extra tests), excellent non-cryptographic security properties (light resistance against both HashDoS and length-extension attacks), low-footprint implementation (efficient memory usage and small code size), no division/modulus/multiplication operators and ultra-fast speed.

Author

ChargeHash was created by William Stafford Parsons as a product of Eightomic.

License

ChargeHash is licensed with BSD-3-Clause.

Implementation

Each mention of ChargeHash refers to each of the 18 following variants individually (chargehash1x32_small, chargehash1x32_medium, chargehash1x32_large, chargehash2x32_small, chargehash2x32_medium, chargehash2x32_large, chargehash4x32_small, chargehash4x32_medium, chargehash4x32_large, chargehash1x64_small, chargehash1x64_medium, chargehash1x64_large, chargehash2x64_small, chargehash2x64_medium, chargehash2x64_large, chargehash4x64_small, chargehash4x64_medium and chargehash4x64_large) implemented in C (requiring the stdint.h header to define an 8-bit, unsigned integral type for uint8_t, a 32-bit, unsigned integral type for uint32_t and a 64-bit, unsigned integral type for uint64_t).

chargehash.c

The byte-copying method (byte-by-byte, memcpy or unaligned pointer casting) in each ChargeHash implementation must be consistent to the byte-copying method in each replaced hash function implementation.

32-Bit

The chargehash1x32_small function uses a uint32_t seed integer to hash a key array of key_length uint8_t integers and return a uint32_t digest.

The chargehash1x32_medium function uses a uint32_t seed integer to hash a key array of key_length uint8_t integers and return a uint32_t digest.

chargehash1x32_large, chargehash2x32_small, chargehash2x32_medium, chargehash2x32_large, chargehash4x32_small chargehash4x32_medium and chargehash4x32_large aren't ready to publish yet.

64-Bit

chargehash1x64_small, chargehash1x64_medium, chargehash1x64_large, chargehash2x64_small, chargehash2x64_medium, chargehash2x64_large, chargehash4x64_small, chargehash4x64_medium and chargehash4x64_large aren't ready to publish yet.