Re: Nortel CES (3DES version) offers false sense of securitywhen usi ng IPSEC

[MCKILLICAN, DONALD]

Rogier Wolff wrote:

> I don't know where people get their information, but tripple-DES uses a 112
> bit key. How they can advertize 128, or even 168 bits of keys I don't know.

In fact, there are a number of different modes for TripleDES.  Some of them
use one key, some of them use two, and some use three.  A commonly used
example of the last named is DES-EDE3.

See, for instance,
<http://www.crypto.nkfurst.edu.tw/infosec/faq/html/3-2-6.html> for more
precise explanations.

Regards,
Donald McKillican
Bell Canada Corporate Security