17 Dec
2003
17 Dec
'03
11:17 p.m.
In article <3.0.32.19970513223226.0074e2bc@netcom13.netcom.com>, Lucky Green <shamrock@netcom.com> wrote:
Contrast this with DESX, which has been proven to be twice as hard as DES, therefore having an effective keylength of 112 bits.
Actually, that's not true. Check out the Rogaway/Kilian paper. It says that, if you've got 2^p known plaintexts, DESX has an effective keylength of at least 118-p bits. So, for instance, if you've got 2^32 known plaintexts, DESX only has an effective keylength of 86 bits. In short, 3DES is (roughly speaking) stronger than DESX.