- From: Paul Lambert <plambert@certicom.com>
- Date: Fri, 23 Apr 1999 13:17:09 -0700
- To: dee3@us.ibm.com
- cc: w3c-xml-sig-ws@w3.org
>>... >>Public key techniques do not need to provide >>recipient unique information. > >### Maybe I misunderstand but if the public key technique being used is >Diffie-Hellman and a recipient has many DH keys, is not "recipient unique >information", in particular an indication of which key to use, needed? You're right. A Diffie-Hellman key exchange/agreement does need a public key indicator and perhaps other information (random stuff). I believe I intended to say - public key digital signatures do not need to provide recipient unique information. So, recipient unique information is used in different ways for each of the major classes of mechanisms that we may support: Recp. Info Security Type ____________________________________ None PK Signature ------------------------------------ Session Key ID Keyed Hash nonce/IV opt. ------------------------------------ Public Key ID Key Agreement random stuff opt. ------------------------------------ Session Key ID Encryption, Session Key Oriented nonce, IV opt, ------------------------------------ Public Key ID Encryption, PK Based encrypted key, opt. IV, opt ------------------------------------ Does our object model and markup representation need to distinguish between the different usage's of Recipient Information? Maybe, maybe not. At this point I need to go off-line and doodle on a few object models. Recipient Unique Information may be just fine as an abstract interface with the particular usage determined by refinement based on security type. Paul dee3@us.ibm.com on 04/23/99 12:13:49 PM To: w3c-xml-sig-ws@w3.org cc: (bcc: Paul Lambert/Certicom) Subject: public versus secret ... Re: Single Key in Originator Information See comments indicated by ###... Donald E. Eastlake, 3rd 17 Skyline Drive, Hawthorne, NY 10532 USA dee3@us.ibm.com tel: 1-914-784-7913, fax: 1-914-784-3833 home: 65 Shindegan Hill Road, RR#1, Carmel, NY 10512 USA dee3@torque.pothole.com tel: 1-914-276-2668 "Paul Lambert" <plambert@certicom.com> on 04/22/99 02:56:51 PM To: "Joseph M. Reagle Jr. (W3C)" <reagle@w3.org> cc: w3c-xml-sig-ws@w3.org (bcc: Donald Eastlake/Hawthorne/IBM) Subject: Re: Single Key in Originator Information Joseph, [...] This restriction on syntax is one of the reasons I'm pushing on differentiating the characteristics of a keyed hash versus public key mechanisms. Keyed hash mechanisms require a Recipient Info field. Public key techniques do not need to provide recipient unique information. ### Maybe I misunderstand but if the public key technique being used is Diffie-Hellman and a recipient has many DH keys, is not "recipient unique information", in particular an indication of which key to use, needed? Paul ### Donald
Received on Friday, 23 April 1999 16:30:56 UTC