Home » Questions » hash

hash

A hash function is any well-defined procedure or mathematical function that converts a large, possibly variable-sized amount of data into a small datum, usually a single integer that may serve as an index to an array (cf. associative array). The values returned by a hash function are called hash values, hash codes, hash sums, checksums or simply hashes.

A cryptographically strong hash function exhibits two features: it is irreversible and it minimizes collisions. Irreversibility means that the original data cannot be reconstructed from its hash. Cf. encryption, which must be reversible (see write-only memory.) A collision occurs when two different sets of data generate the same hash.

Hash functions are related to (and often confused with) checksums, check digits, fingerprints, randomization functions, and error-correcting codes. Although these concepts overlap to some extent, each has its own uses and requirements and is designed and optimized differently.

NOTE: The content of this tag was originally posted at StackOverflow.com

0 votes
0 answers
12k views
this is test
  • demo asked 10 years ago
1 vote
79k views
It is currently said that MD5 is partially unsafe. Taking this into consideration, I’d like...
  • Tina asked 16 years ago
  • last active 9 years ago
Showing 2 results