non-standard CFB (Re: Lutz formal spec / ROT-13 persists)

Jon Callas jon at
Tue Feb 17 19:16:55 CET 1998

At 12:26 AM 2/13/98 GMT, Adam Back wrote:
   Werner Koch <wk at> writes:
   > By the way, is is really required that PGP's strange CFB mode is
   > required for other ciphers that IDEA?
   I argued against earlier on list, and argued for the non-standard CFB
   to be depracated for all ciphers.  However I think pgp5.x already is
   deployed with non-standard CFB for CAST (and I presume 3DES also).
We're stuck with the non-standard CFB (which is used for all ciphers) until
OpenPGP v2. It's needed for backwards compatibility. Sorry.


Jon Callas                                  jon at
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