One-way compression function

In cryptography, a one-way compression function is a function that transforms two fixed-length inputs into a fixed-length output. The transformation is "one-way", meaning that it is difficult given a particular output to compute inputs which compress to that output. One-way compression functions are not related to data compression, which by definition can be inverted exactly (lossless compression) or approximately (lossy compression) to the original data. One-way compression functions are for instance used in the Merkle–Damgård construction inside cryptographic hash functions.

One-way compression function

In cryptography, a one-way compression function is a function that transforms two fixed-length inputs into a fixed-length output. The transformation is "one-way", meaning that it is difficult given a particular output to compute inputs which compress to that output. One-way compression functions are not related to data compression, which by definition can be inverted exactly (lossless compression) or approximately (lossy compression) to the original data. One-way compression functions are for instance used in the Merkle–Damgård construction inside cryptographic hash functions.