[Neil Humphreys]

Hi all, I have an app that requires 2 types of secure communications: -one fully secured channel with encrypted data -one fully secured channel, *except* that the data itself is not secret, and does not need any encryption.   Hence, I would be grateful if someone could spell out what the following cipher suite provides:   DES-CBC3-SHA   that the following one doesn't:   NULL-SHA   with regards to the following security features:   1. secrecy (encryption) 2. authentication (sender/receiver validation) 3. prevention of message tampering   One other thing .. once the handshake is over, is there much CPU/network bandwidth overhead in using NULL-SHA, compared with unsecured tcp?   Many thanks! Neil Humphreys