KEY

Information (usually a sequence of random or pseudorandom binary digits) used initially to set up and periodically change the operations performed in crypto -equipment for the purpose of encrypting or decrypting electronic signals, for determining electronic counter-countermeasures patterns ( e.g. , frequency hopping or spread spectrum ), or for producing other key. Note: "Key" has replaced the terms "variable," "key(ing) variable," and "cryptovariable." [ NIS ]