Threefry

Threefry is a family of fast non-cryptographic hash functions developed by John Tulley. These functions are designed for speed and good statistical properties, making them suitable for applications like hash tables, random number generation, and data integrity checks. Threefry's design is based on a permutation function that uses a combination of bitwise operations such as XOR, addition, and rotations.

The Threefry algorithm takes a key, a nonce, and an input message as parameters. It processes the input message in blocks, applying a series of rounds of transformations. The number of rounds is typically determined by the desired security level or performance trade-off. A key feature of Threefry is its use of the "counter mode" of operation, where a counter is incremented with each block processed. This helps to ensure that identical inputs with different keys or nonces produce different outputs.

Threefry has gained attention for its simplicity and efficiency, often outperforming other hash functions in benchmarks. It is part of the Xorshift family of generators and has been used in various software projects. The Threefry algorithm is not intended for cryptographic security against malicious attackers but rather for situations where speed and good distribution of hash values are paramount.