DES as a stream cipher

Karl A. Siil karl at geoplex.com
Mon Apr 22 22:13:12 PDT 1996


Folks,

As this sounds like a previously solved problem, I wanted to find out about
using DES (or any block cipher) as a stream cipher, i.e., in a manner that
keeps input and output data length equal. I don't want to use a true stream
cipher, as I want to use the same key for multiple messages and stream
ciphers tend to place the bulk of their overhead in the re-key. Since stream
ciphers have "memory," I would have to "re-key" to the same key for each of
my messages. I would rather key something like DES once and run it in CBC
mode or use some other form of IV.

Help or pointers to help are greatly appreciated.

                                        Karl







More information about the cypherpunks-legacy mailing list