Subject: Certificate confirmation

From: "Christopher Williams" <[email-masked]>
Date: Thu, 6 Apr 2000 14:35:00 +0100

In the first version of RFC 2510, POP of an encryption key could be
established by decrypting a certificate sent by a CA and using the symmetric
key used to encrypt it as the input to a password-based MAC used to protect
a subsequent PKIConfirm message.

The second version adds the certificate confirmation message which
incorporates a hash of the certificate.  This will effectively prove POP of
an encryption key if the certificate was encrypted.  Does the protocol still
expect the confirmation message to be protected by a password-based MAC
which has the symmetric key used to encrypt the certificate as its input?

Christopher Williams

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

---

From: Carlisle Adams <[email-masked]>
Date: Thu, 6 Apr 2000 09:59:20 -0400

Hi Chris,

> ----------
> From: 	Christopher Williams[SMTP:[email-masked]]
> Sent: 	Thursday, April 06, 2000 9:35 AM
> To: 	PKIX Mailing List
> Subject: 	Certificate confirmation
> 
 
No, this is no longer expected, but it is certainly permissible.  The MAC
based on this key is no longer needed to do POP, but the message still
requires some form of integrity.  So, you can do a MAC based on this key, or
a MAC based on some other shared password, or a signature, or whatever (as
long as it is clear to the receiver what you're doing and which key you're
using).

Carlisle.