<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)

<communications> A channel (on a BRI or PRI line) used to carry control information, to set up connections on the associated bearer channels. The name wasn't too bad back when users were sending voice (not data) over the {bearer channels}, but in 1997 it's quite a misnomer. (1997-03-10)

Channel was the name of a lightvessel station located in the English Channel between 1979 and August 2021, when it was replaced with a light buoy. It was also one of the 22 coastal weather stations whose conditions were reported in the BBC Shipping Forecast.