Re: Decryption Transform

At 16:18 6/29/2001, John Cowan wrote:
>Now on your "sign only what is seen" principle, shouldn't Alice sign the
>title and price only?  Then we have a signature covering the
>whole plaintext document, and another covering part of the plaintext
>document.  ZipPay can decrypt Bob's info and then verify both
>signatures: no need for verify-decrypt-verify, although of course that
>will work as well.

Yes, this is possible, but I didn't want to confuse the partial signature 
possibility with the verify-decrypt-verify in the simple scenario... 
Actually, with the proposed text, we could add a parenthesis making this 
clear but I'm not sure if it confuses the issue...

/+(Alice's signature over Bob's encrypted data does not mean she signs its 
clear text equivalent; as Alice only "signs what she sees", she signs the 
encrypted data and nothing more.)+/


--
Joseph Reagle Jr.                 http://www.w3.org/People/Reagle/
W3C Policy Analyst                mailto:reagle@w3.org
IETF/W3C XML-Signature Co-Chair   http://www.w3.org/Signature
W3C XML Encryption Chair          http://www.w3.org/Encryption/2001/

Received on Monday, 2 July 2001 11:42:24 UTC