From: Matthew J Ghio <mg5n+@andrew.cmu.edu>
Date: Mon, 28 Feb 94 12:25:20 PST
To: Cypherpunks Mailing List <cypherpunks@toad.com>
Subject: DES Question
Message-ID: <ghQZ=Nq00awT82I0UR@andrew.cmu.edu>
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When using DES to encrypt email addresses, the total amount of data to
be encrypted would be only 3 or 4 eight-byte DES blocks.  My question
is: Would CBC or CFB really be effective for such a small amount of
data?  Or would it be better to encrypt multiple times with
transpositions in between (ie '4x3' DES as was described earlier in
cypherpunks)?

Second question: The DES code that I have (not written by me) has a
comment section which describes filling all 16 subkeys seperately,
thereby allowing a 128 byte key.  Is there any significant advantage to
doing this?  Is there any reason that I should not do it?

What is the purpose of the initial and final permutations?