(IDEA) A coNveNtioNal eNcryptioNalgorithm, writteN by Xuejia Lai aNd James Massey, iN 1992. It is a block cipher, coNsidered to be the best aNd most secure available, aNd operates oN 64-bit blocks with a 128 bit key. It is used by Pretty Good Privacy. (1996-03-07)