# Dht nodes not updating

A hash function should in theory be a very quick, stable and deterministic operation.A hash function may not always lend itself to being of O(1) complexity, however in general the linear traversal through a string or byte array of data that is to be hashed is so quick and the fact that hash functions are generally used on primary keys which by definition are supposed to be much smaller associative identifiers of larger blocks of data implies that the whole operation should be quick, deterministic and to a certain degree stable.

When LUTs are employed in a hash function they are typically used in a combination of one or more of the following ways: is the block of the message in the current mixing round and |P| is the size of the lookup table.As far as the composition of the LUTs are concerned, the types of values (numbers) used are typically implementation defined.Sometimes they may be a list of prime numbers, other times they may be a set of values that possess specific bit patterns .Some implementations will also attempt to integrate side information such as the total number of bits hashed, or mixes with magic numbers based on the final value of the IS.The "Mix" operation denoted above takes as input the internal state and the current message block, performs some computation and returns the value of the internal state.

They are used to create keys which are used in associative containers such as hash-tables.