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The following archive was created by hippie-mail 7.98617-22 on Fri Aug 21 1998 - 17:20:41 ADT
Paulo Barreto (pbarreto@nw.com.br)
Mon, 20 Jul 1998 20:15:05 -0300
At 12:20 1998.07.20 -0700, Bob Baldwin wrote:
>Actually, IBM has enforced its patents for digest functions
>based on DES (or any other block cipher) called MDC-2
>and MDC-4. It also has a patent on using DES to create
>a 40-bit keyspace version called CDMF. Both of these
>"weird new modes" for DES are patented and IBM does in
>fact enforce them.
These seem to be patents on the digest function constructions, not the DES
patent properly: as you yourself said, the patents apply to any other block
cipher as well (hence, say, to MDC-4 with DES replaced by Blowfish).
Paulo.
P.S. BTW, I seem to recall that both MDC-2 and MDC-4 were broken.
The following archive was created by hippie-mail 7.98617-22 on Fri Aug 21 1998 - 17:20:41 ADT