Re: Double Encryption Illegal?
Date: 16 Sep 2000 17:01:56 GMT
Message-ID: <8q0924$kpq$1_at_nntp.itservices.ubc.ca>
In <8pvejh$g03$1_at_news.netvision.net.il> "PRdO" <prdo_at_barak-online.net> writes:
>IMHO double encryption *does not* add security, i.e., double encryption in
>128-bit doesn't equal better encryption.
>(since encryption uses random keys, "randoming" again the data would not
>lead to more secure data).
It might. A) it removes the structure in the "cleartext" of the top layer for finding the key with exhaustive search. B) It makes the strength at least equal to that of the strongest of the two encryption shemes. Of course these comments are not absolute. For example a double encryption scheme in which one used say DES in one round and DES inverse in the next round with the same key is nowhere near as strong as any one of those two rounds:-)
But for example DES applied to ROT13 is certainly stronger than ROT13. Thus if one of the schemes is suddenly broken, double encryption still protects the contents with the other scheme. Received on Sat Sep 16 2000 - 19:01:56 CEST