Applied Crypto 2nd Edition - page 334-335. Brief stuff: Block Cypher (symetrical), 64 bit key, 64 bit block size "The S-boxes are implemenation dependent, but not key dependent." resistant to differential and linear cryptanalysis "Northern Telecom is using CAST in their Entrust security software package for Macintoshes, PCs, and UNIX workstations. The particular S-boxes they chose are not public. The Candadian government is evaluating CAST as a new encryption standard. CAST is patent pending." If you don't have the book - GET IT! ;-) Dan

From: "Stephen A. Gutknecht" <sgutknec@computek.net> To: "'cypherpunks@toad.com'" <cypherpunks@toad.com> Subject: RE: Nortel "Entrust"

I too would like to see an open discussion on this. Microsoft uses this for their new Exchange Server client/server email product....

---------- From: Jonathon Fletcher[SMTP:jonathon@japan.sbi.com] Sent: Friday, March 01, 1996 10:17 AM To: cypherpunks@toad.com Subject: Nortel "Entrust"

Can anyone tell me anything about a product called "Entrust", by Nortel (Northern Telecom). The notes talk about the software using DES ("which employs a 56-bit key") so I guess it's single DES, not triple DES. It also mentions a proprietary algorithm called CAST.

Is this worthy of further investigation, or is it suspect ? What is CAST, and would it be classed as snake oil ?

------------------------------------------------------------------ Dan Oelke Alcatel Network Systems droelke@aud.alcatel.com Richardson, TX