Subject: RE: generation of private keys

From: Peter Sylvester <[email-masked]>
Date: Thu, 3 Dec 1998 16:07:53 +0100

Is there someone who likes to have an extension that tells that
the CA has not performed a proof of presence of a secret key.

It seems quite useful in some contexts that a CA just certifies
the fact that it knows how to get to the real entity by using the
subjectname, but not that the entity actually owns the secret.

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From: Dan Geer <[email-masked]>
Date: Thu, 03 Dec 1998 10:59:44 -0500

It seems to me that nearly anything that goes in a CPS
or which a relying party would need can be summed up in
a boolean "CA warrants this certificate" and, if both
you care and the bit is zero, you either self-insure,
sell your risk, or run screaming from the room.  Otherwise,
we will die the death of a thousand nuanced extensions.

--dan

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From: Juergen Walter <[email-masked]>
Date: Fri, 04 Dec 1998 16:38:05 +0100

Hallo Dan,

comments in line,

Dan Geer wrote:
> a boolean "CA warrants this certificate" 

[Juergen] I think the warranty is given after the certificate was signed
by the CA. Proof of possession is MANDATED by the CRMF draft. In the
result, this is a redundant bit. The point is what
level of warranty and assurance, respectively. [Juergen]

>and, if both

[Juergen] I agree. The relying party would not accept any certificate
when he/she/it has no trust in the issuing authority (say CA) wherever
the key has been generated.

I see the risk of long vehicle certificates too.

It is a common practise that CAs provide assurance level using different
CA`s private key for each level. There may be in addition a pointer to
the underlying Certification Practise Statement. The framework given in
[PKIX CPS] is comprehensive. Surely, some CPS nowadays in use needs
improvement.

[Juergen]
> --dan

Juergen
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