-----BEGIN PGP SIGNED MESSAGE----- In article <199510270413.VAA29718@ix7.ix.netcom.com>, John Lull <lull@acm.org> wrote:
Even for 2DES, or for 3-key 3DES, doesn't a meet in the middle attack require on the order of 2^56 words of memory?
Actually, as it turns out, van Oorschot & Wiener have a recent paper which describes how to break 2DES without the huge space requirements without sacrificing too much time (by using their parallel collision search method). They estimated the cost to break 2DES via specialized hardware, and decided that breaking 2DES was only about 2^14 times as costly as breaking DES. The conclusion to take away from this is simple: double encryption doesn't give you much extra security over single encryption. Don't use double encryption. - --- [This message has been signed by an auto-signing service. A valid signature means only that it has been received at the address corresponding to the signature and forwarded.] -----BEGIN PGP SIGNATURE----- Version: 2.6.2 Comment: Gratis auto-signing service iQBFAwUBMJLKmSoZzwIn1bdtAQEk5gF/VtAgBNgB6o8SrTWSSMaciikdzoVCIqYF JdXxs4pWt6ueY8WVsSEj5yU5EKAT0/4M =6YNF -----END PGP SIGNATURE-----