Subject: Message protection and key update

From: "Christopher Williams" <[email-masked]>
Date: Thu, 4 May 2000 16:53:04 +0100

Consider the following scenario:

I am enrolled in a PKI and have a signing-key pair that I wish to update.  I
send a key update request containing a new public key.  I sign the message
using my old private key.  The request is granted by the CA so I send a
certificate confirm message.

I assume that I sign this message with my NEW private key.  Is this correct?

Also, does this signature provide implicit POP of the private key?  After
all, the signature is over the hash of a certificate containing the matching
public key.  If it does provide implicit POP, should the POP options be
expanded?

Christopher Williams

Software engineer, NetLexis Ltd.
Solutions for secure electronic commerce
http://www.netlexis.com

---

From: Carlisle Adams <[email-masked]>
Date: Thu, 4 May 2000 13:17:31 -0400

Hi Chris,

> ----------
> From: 	Christopher Williams[SMTP:[email-masked]]
> Sent: 	Thursday, May 04, 2000 11:53 AM
> To: 	PKIX Mailing List
> Subject: 	Message protection and key update
> 
 
You can sign with the new private key if you wish, but the old private key
would be fine as well (and, in fact, it may be slightly preferable to have
the consistency of a single method for all the messages in an exchange).

> public key.  If it does provide implicit POP, should the POP options be
 
Don't think of this as providing implicit POP.  [If signing the hash of the
cert is POP, what about the hash-of-the-hash of a cert?  What about the
hash-of-the-hash-of-the-hash of the cert?  I think it's best not to go down
this route at all.]  This is simply authentication and integrity protection
on the message.

Carlisle.