<cryptography> An encryption algorithm created by the NSA (National Security Agency) which encrypts 64-bit blocks of data with an 80-bit key. It is used in the Clipper chip, a VLSI device with an ARM processor core, which is intended to perform cryptographic operations while allowing the security agencies listen in.
There are (apparently) two agencies, both of whom have to agree that there is a valid reason to decode a message. Don't laugh, they are serious.
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Nearby terms: S/Key « Skill « Skim « SkipJack » SKOL » skolemisation » S-K reduction machine