[3062] in cryptography@c2.net mail archive
Multiple-DES and block size
daemon@ATHENA.MIT.EDU (Steve Reid)
Fri Jul 24 05:43:32 1998
Date: Thu, 23 Jul 1998 12:56:57 -0700 (PDT)
From: Steve Reid <sreid@alpha.sea-to-sky.net>
To: cryptography@c2.net
Are there any good multiple-encryption schemes that also increase block
length?
I seem to recall a multiple-encryption construction to double the block
length of a cipher. The idea was to create a four-round Feistel cipher
which used DES or some other block cipher as the f() function.
This would seem to be faster than 3DES (1/2 the speed of DES instead of
1/3) and provide better resistance to birthday attacks (128-bit block)
but it's not much good if it's not well-studied. Does anyone know what
I'm talking about, and if this construction is considered secure or not?
