Developed by Xuejia Lai
and James Massey in 1992. A block cipher, IDEA operates on 64-bit blocks with a
128-bit key and is considered to be very secure. IDEA is used by Pretty Good Privacy (PGP), a very
secure public key encryption application for MS-DOS, UNIX, and VAX/VMS. Originally written by Philip
Zimmermann, PGP was later improved by Hal Finney, Branko Lankester, and Peter
Algorithm; Pretty Good Privacy (PGP); UNIX.
Farlex, Inc. The Free Dictionary: International Data Encryption Algorithm.
[Online, 2004.] Farlex, Inc. Website.