Change Set: DES Date: 26 January 2000 Author: Duane Maxwell

This class implements the Data Encryption Standard (DES) block cipher per ANSI X3.92. It requires the presence of the 'DESPlugin'. At some future date the functionality of the plugin may be provided in pure Smalltalk, but the slowness would be prohibitive for anything other than trivial usage. The main barrier to translation is the heavy use of zero-based indexing of arrays.

How to use: you first provide an 8-byte key which will be used to encode and decode the data. Internally, this is 'cooked' into a 32-word format to speed up the encryption process. The data is then sent in 8-byte packets to be encoded or decoded. You must externally account for padding. See the 'testing' category on the class side for examples.

As of this date (1/26/2000), the U.S. Government has lifted many of the previous restrictions on the export of encryption software, but you should check before exporting anything including this code.

Macintosh plugin included.

Duane, this is outstanding stuff!!! I am presently working on some OpenPGP protocol routines, and this code will fill in the meat quite nicely.