A function that maps a bit string of arbitrary length to a fixed length bit string and is expected to have the following three properties:
1) Collision resistance (see Collision resistance),
2) Preimage resistance (see Preimage resistance) and
3) Second preimage resistance (see Second preimage resistance).
Approved cryptographic hash functions are specified in [FIPS 180-3].

**Source(s):**

NIST SP 800-106

See Hash function.

**Source(s):**

NIST SP 800-57 Part 1 Rev. 3 [Superseded]

NIST SP 800-57 Part 1 Rev. 4

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

**Source(s):**

NIST SP 800-56A Rev. 2 under Hash function

NIST SP 800-56B Rev. 1 under Hash function

An algorithm that computes a numerical value (called the hash value) on a data file or electronic message that is used to represent that file or message, and depends on the entire contents of the file or message. A hash function can be considered to be a fingerprint of the file or message.

**Source(s):**

NIST SP 800-152 under Hash function

A function that maps a bit string of arbitrary (although bounded) 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, and
2. (Collision resistant) It is computationally infeasible to find any two distinct inputs that map to the same output.

**Source(s):**

NIST SP 800-57 Part 1 Rev. 4 under Hash function

A function that maps a bit string of arbitrary length to a fixed-length bit string. The function is expected to have the following three properties:
1. Collision resistance (see Collision resistance),
2. Preimage resistance (see Preimage resistance) and
3. Second preimage resistance (see Second preimage resistance).
Approved hash functions are specified in [FIPS 180-4].

**Source(s):**

NIST SP 800-107 Rev. 1 under Hash function

A function that maps a bit string of arbitrary length to a fixed length bit string. Approved hash functions are designed to satisfy the following properties:
1. (One-way) It is computationally infeasible to find any input that maps to any pre-specified output, and
2. (Collision resistant) It is computationally infeasible to find any two distinct inputs that map to the same output.
Approved hash functions are specified in FIPS 180-3.

**Source(s):**

NIST SP 800-108 under Hash function

A function that maps a bit string of arbitrary length to a fixed-length bit string. Approved hash functions are designed to satisfy the following properties:
1. (One-way) It is computationally infeasible to find any input that maps to any pre-specified output, and
2. (Collision resistant) It is computationally infeasible to find any two distinct inputs that map to the same output.
Approved hash functions are specified in FIPS 180.

**Source(s):**

NIST SP 800-56C under 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, and 2. (Collision resistant) It is computationally infeasible to find any two distinct inputs that map to the same output.

**Source(s):**

NIST SP 800-57 Part 1 Rev. 3 under Hash function [Superseded]