Customized hash function A hash function can be designed to exploit existing entropy in the keys. If the keys have leading or trailing zeros, or particular fields that are unused, always zero or some other constant, or generally vary little, then masking out only the volatile bits and hashing on those will provide a better and possibly faster hash function. Selected divisors or multipliers in the division and multiplicative schemes may make more uniform hash functions if the keys are cyclic or have other redundancies.
cUSTomized HaSh funCtioN a haSH fUnctIon CAn be designed To explOIt exIsting eNTroPy in thE keys. if the kEYs have LeADINg or trAILing zeros, Or PaRticUlAR fields that ARe UNUsEd, alwAYs zeRo or some other conSTant, or generally vARy LITtLe, THEN mASking Out onlY thE vOlaTile bits aNd HashinG oN THose WIlL pRovide A bettEr And posSiBLy FastEr hash funcTIoN. seleCTeD DivISors OR mULtipLiErs In tHe dIVISioN and multipliCAtive schemeS may make More uniform hasH funCTIonS if the keys aRe cycLic or have other redUNDANcIeS.