In computer science, a hash collision or clash is when two pieces of data in a hash table share the same hash value. The hash value in this case is derived from a hash function which takes a data input and returns a fixed length of bits.

<programming> (Or "hash clash") When two different keys hash to the same value, i.e. to the same location in a {hash table}. ESR once asked a friend what he expected Berkeley to be like. The friend replied, "Well, I have this mental picture of naked women throwing Molotov cocktails, but I think that's just a collision in my hash tables." [Jargon File] (1995-01-23)

hash coding

Ship collision is the structural impact between two ships or one ship and a floating or still object such as an iceberg.Database Of Ship Collisions With Icebergs Ship collisions are of particular importance in marine accidents.

<algorithm> (Or "message digest function") A {one-way function} which takes a variable-length message and produces a fixed-length hash. Given the hash it is computationally infeasible to find a message with that hash; in fact one can't determine any usable information about a message with that hash, not even a single bit. For some one-way hash functions it's also computationally impossible to determine two messages which produce the same hash. A one-way hash function can be private or public, just like an encryption function. MD5, SHA and Snefru are examples of public one-way hash functions. A public one-way hash function can be used to speed up a public-key digital signature system. Rather than sign a long message, which can take a long time, compute the one-way hash of the message, and sign the hash. {sci.crypt FAQ (ftp://src.doc.ic.ac.uk/usenet/usenet-by-group/sci.crypt/)}. (2001-05-10)

In cryptography and computer science, a hash tree or Merkle tree is a tree in which every "leaf" (node) is labelled with the cryptographic hash of a data block, and every node that is not a leaf (called a branch, inner node, or inode) is labelled with the cryptographic hash of the labels of its child nodes. A hash tree allows efficient and secure verification of the contents of a large data structure.

Collision Course ( Collision with Chronos) is the fourth novel by the science fiction author Barrington J. Bayley.

<algorithm, cryptography> (SHA) A one-way hash function developped by NIST and defined in standard FIPS 180. SHA-1 is a revision published in 1994; it is also described in ANSI standard X9.30 (part 2). (2003-04-12)

The Secure Hash Algorithms are a family of cryptographic hash functions published by the National Institute of Standards and Technology (NIST) as a U.S.

In aviation, a mid-air collision is an accident in which two or more aircraft come into unplanned contact during flight. Owing to the relatively high velocities involved and the likelihood of subsequent impact with the ground or sea, very severe damage or the total destruction of at least one of the aircraft usually results.