CityHash128

CityHash128 is a non-cryptographic hash function developed by Google. It is designed to provide fast and efficient hashing of 128-bit keys. The function is part of the CityHash family of hashing algorithms, which are optimized for performance on modern CPUs.

The CityHash128 algorithm takes a variable-length byte string as input and produces a 128-bit hash value. It employs a series of bitwise operations, multiplications, and additions to mix the input data and generate the output. The design aims to achieve good distribution of hash values and minimize collisions, making it suitable for applications like hash tables and data integrity checks.

One of the key features of CityHash128 is its speed. It is generally faster than many other common hashing algorithms, particularly for short to medium-length inputs. This performance advantage makes it a popular choice in scenarios where hashing speed is critical, such as in large-scale data processing and in-memory data structures.

CityHash128 is not intended for cryptographic purposes, meaning it is not designed to be resistant to malicious attacks like hash collisions found in cryptographic hashes. Its strength lies in its speed and good distribution properties for non-adversarial use cases. The algorithm is available as open-source code, allowing for its use and integration into various software projects.