CityHash64 and Finding Collision Samples for it
CityHash is a modern family of hash functions for strings (variable-length arrays) that provides one of the best performance and quality, requiring only standard 64-bit instructions for optimal performance. This makes it very useful "general-purpose" hash. In particular, CityHash64 hashes to 64-bit value, which makes it primary function of choice on 64-bit platform. For some tests (e.g. containers), it's beneficial to know which pairs of strings will produce same hash value (collision). Finding collisions for well-designed hash function could be difficult - since brute force most likely will be most viable approach. I've recently have calculated some collisions for CityHash64 using multi-threaded birthday attack algorithm. So I provide two such pairs there for your convenience: StrA=" oH]pPZccPmOEHjBW " StrB=" vm`sd|obCXIKJ}aE " CityHash64= DCBE2B1930540000 StrA=" ?];lLLK:R_@XddTg " StrB=" bgW^Wi]IkQgDM3WW " CityHa...