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 prespecified output.   2) Collision Resistant. It is computationally infeasible to find any   two distinct inputs that map to the same output.   SOURCE: SP 800-63; FIPS 201 Hash Function – A mathematical function that maps a string of arbitrary length (up to   a predetermined maximum size) to a fixed length string.   SOURCE: FIPS 198   A function that maps a bit string of arbitrary length to a fixed length   bit string. Approved hash functions are specified in FIPS 180 and are   designed to satisfy the following properties:   1. (One-way) It is computationally infeasible to find any input that   maps to any new prespecified output, and   2. (Collision resistant) It is computationally infeasible to find any two   distinct inputs that map to the same output.   SOURCE: FIPS 186 Hash Total – Value computed on data to detect error or manipulation. See   Checksum.