Hash Function

A function used to create a hash value from binary input. The hash is substantially smaller than the text itself, and is generated by the hash function in such a way that it is extremely unlikely that some other input will produce the same hash value.

A function used to produce a hash code from the arbitrary contents of an object. Classes can override the hashValue method, inherited from the Object class, to define their own hash function.

A function that maps a bit string of arbitrary length to a fixed length bit string. Approved hash functions satisfy the following properties: 1) One-Way. It is computationally infeasible to find any input that maps to any pre-specified output. 2) Collision Resistant. It is computationally infeasible to find any two distinct inputs that map to the same output.

1. A mathematical function that maps values from a large (or very large) domain into a smaller range, and that reduces a potentially long message into a "message digest" or "hash value" or that is sufficiently compact to be input into a digital signature algorithm. Note: A "good" hash function is one that results from applying the function to a (large) set of values that are evenly (and randomly) distributed over the range. 2. A function that maps values from a (possibly very) large set of values to a smaller range of values [10181-1]. 3. A (mathematical) function which maps values from a (possibly very) large set of values into a smaller range of values [10181-2]