Subject: Certificate suspension

From: Stephen Wilson <[email-masked]>
Date: Wed, 23 Jan 2008 12:49:47 +1100

I'm wondering to what extent is X.509 certificate suspension used in 
practice?

Most if not all publicly visible CPs describe suspension, in almost 
exactly the same way as they do revocation.  Yet in my experience, I 
cannot ever recall a commercial CA or a closed/vertical PKI actually 
doing suspensions.

To my mind, suspension is riddled with difficulties, not anticipated by 
the way CRLs work.  I could go into my concerns in a separate e-mail. 
But if anyone can point to suspension being offered in practice (or 
failing that, a critique of suspension) that would be appreciated!

Thanks in advance.

Cheers,

Stephen Wilson
Managing Director
Lockstep

Phone +61 (0)414 488 851

www.lockstep.com.au
-------------------
  * Lockstep Technologies: ICT Secrets of Innovation Finalist 2007
  * Lockstep Technologies: Anthill / PwC Cool Company Finalist 2007
-------------------
Lockstep Consulting provides independent specialist advice and analysis
on authentication, PKI and smartcards.  Lockstep Technologies develops
unique new smart ID solutions that safeguard identity and privacy.

---

From: Yoav Nir <[email-masked]>
Date: Wed, 23 Jan 2008 10:41:27 +0200

If you browse the archives of this mailing list, you will find in late  
November and early December of 2007 a discussion of "on-hold  
certificates in CRLs"

Most appear to share your sentiments about suspension, but apparently  
there are some regulatory requirements that are satisfied by the  
possibility of suspension.

Yoav

On Jan 23, 2008, at 3:49 AM, Stephen Wilson wrote:

> To my mind, suspension is riddled with difficulties, not anticipated  
> by the way CRLs work.  I could go into my concerns in a separate e- 
> mail. But if anyone can point to suspension being offered in  
> practice (or failing that, a critique of suspension) that would be  
> appreciated!
>
> Thanks in advance.
>
> Cheers,
>
> Stephen Wilson

---

From: "Ignacio Alamillo" <[email-masked]>
Date: Wed, 23 Jan 2008 10:27:29 +0100

Under Spanish law, suspension is a legal requirement (not a strictly
enforced one, but a requirement after all) and therefore many CA have
implemented it, and it is actually used.

Best,

Ignacio Alamillo
Catalan Certification Authority

> -----Mensaje original-----
> De: [email-masked] 
> [mailto:[email-masked]] En nombre de Stephen Wilson
> Enviado el: dimecres, 23 / gener / 2008 02:50
> Para: [email-masked]
> Asunto: Certificate suspension
> 
> 
> 
> 
www.lockstep.com.au
-------------------

---

From: Johannes Merkle <[email-masked]>
Date: Wed, 23 Jan 2008 10:29:20 +0100

Stephen,

for the Austrian social insurance card (e-card) two kind of
certificates are offered, which can only be suspended. If not
un-suspended within 72 hours, they are revoked. The reason for this
is that the card issuer was afraid of too many people temporarily
mislaying their cards and requesting revocation.

If you know German or know someone to translate, here is the CPS:
http://www.signatur.rtr.at/repository/csp-hauptverband-cps-vsig-092-20060726-de.pdf

regards,
Johannes Merkle

---

From: Alfredo Esposito <[email-masked]>
Date: Wed, 23 Jan 2008 17:18:02 +0100

For the Italian law the CSP SHALL manage suspension, with a cumbersome
charge of related issues.

regards

Dino Esposito

Johannes Merkle wrote:

Stephen,

regards,
Johannes Merkle

Thanks in advance.

Cheers,

Stephen Wilson
Managing Director
Lockstep

Phone +61 (0)414 488 851

www.lockstep.com.au
-------------------

---

From: "Terwilliger, Ann" <[email-masked]>
Date: Wed, 23 Jan 2008 08:28:47 -0800

Actually we do use suspension.  It gives us a means of preventing the
certificate from being relied upon (assuming of course that the relying
party application recognizes the 'on hold' entry in the CRL) while we
complete the investigation to see if there really is a valid reason to
revoke the certificate.  By suspending the certificate we still have the
option to reinstate it without requiring the certificate requestor to
generate a new key pair/certificate request.  

Ann Terwilliger, CISSP | Product Director|
Visa Incorporated| 650.432.3661

NOTICE
This email message and any attachments are intended only for the use of
the addressee named above and may contain information that is privileged
and confidential.  If you are not the intended recipient, any
dissemination, distribution, or copying is strictly prohibited.  If you
received this email message in error, please immediately notify the
sender by replying to this email message or by telephone to the Visa
switchboard at 1(650) 432-3200.  Thank you.

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
On Behalf Of Stephen Wilson
Sent: Tuesday, January 22, 2008 5:50 PM
To: [email-masked]
Subject: Certificate suspension

Thanks in advance.

Cheers,

Stephen Wilson
Managing Director
Lockstep

Phone +61 (0)414 488 851

www.lockstep.com.au
-------------------

---

From: Stephen Kent <[email-masked]>
Date: Wed, 23 Jan 2008 11:47:59 -0500

>generate a new key pair/certificate request.

A new cert request need not entail a new key pair.  The bundling of 
these two makes the process more painful for the Subject, and thus 
provides greater justification for suspension vs. revocation, but 
such bundling is NOT required by the standards.

Steve

---

From: "Andrews, Rick" <[email-masked]>
Date: Wed, 23 Jan 2008 10:58:27 -0800

Stephen,

VeriSign has supported suspension in only one case that I know of, where
we were issuing certs to be used with Identrus-compliant applications.
No one else requests it.

-Rick 

> From: [email-masked] 
> [mailto:[email-masked]] On Behalf Of Stephen Wilson
> I'm wondering to what extent is X.509 certificate suspension 
> used in practice?
> 
> Most if not all publicly visible CPs describe suspension, in 
> almost exactly the same way as they do revocation.  Yet in my 
> experience, I cannot ever recall a commercial CA or a 
> closed/vertical PKI actually doing suspensions.
> 
> To my mind, suspension is riddled with difficulties, not 
> anticipated by the way CRLs work.  I could go into my 
> concerns in a separate e-mail. 
> But if anyone can point to suspension being offered in 
> practice (or failing that, a critique of suspension) that 
> would be appreciated!
> 
> Thanks in advance.
> 
> Cheers,
> 
> Stephen Wilson
> Managing Director
> Lockstep
> 
> Phone +61 (0)414 488 851
> 
> www.lockstep.com.au
> -------------------
> Lockstep Consulting provides independent specialist advice 
> and analysis on authentication, PKI and smartcards.  Lockstep 
> Technologies develops unique new smart ID solutions that 
> safeguard identity and privacy.
> 
> 
> 
>

---

From: Massimiliano Pala <[email-masked]>
Date: Wed, 23 Jan 2008 14:20:37 -0500

Hi all,

I guess that the problem with the current PKIX solution on suspension is
that it is just an extended revocation status - this means that it is
just a sub-case of revocation. In many cases this is not what you need,
and when some laws require "suspension" they have not a clear idea of
what is it, actually.

I wonder how many "non-ad-hoc" applications actually know how to correctly
handle suspension... we are still facing interoperability issues between
PKIs with respect to this issue, I guess...

Later,
Max

-- 

Best Regards,

	Massimiliano Pala

--o------------------------------------------------------------------------
Massimiliano Pala [OpenCA Project Manager]            [email-masked]
                                                  [email-masked]

Dartmouth Computer Science Dept               Home Phone: +1 (603) 397-3883
PKI/Trust - Office 063                        Work Phone: +1 (603) 646-9179
--o------------------------------------------------------------------------

---

From: Russ Housley <[email-masked]>
Date: Wed, 23 Jan 2008 15:19:02 -0500

I have said many times that I wish we had deprecated certificate 
suspension in RFC 2459 and all of its successors.  As you say, it is 
riddled with difficulties, and those have been discussed many times 
over the years.

When we were working on RFC 2459 someone from the financial community 
argued that it was needed.  So, it was not deprecated.   You can look 
at the archives for the recurring discussion.

Russ

At 08:49 PM 1/22/2008, Stephen Wilson wrote:

>I'm wondering to what extent is X.509 certificate suspension used in practice?
>
>by the way CRLs work.  I could go into my concerns in a separate 
>e-mail. But if anyone can point to suspension being offered in 
>practice (or failing that, a critique of suspension) that would be appreciated!
>
>Thanks in advance.
>
>Cheers,
>
>Stephen Wilson
>Managing Director
>Lockstep
>
>Phone +61 (0)414 488 851
>
>www.lockstep.com.au
>-------------------

---

From: "Todd E. Johnson" <[email-masked]>
Date: Wed, 23 Jan 2008 19:45:05 -0500

The U.S. Treasury does not support suspension mainly due to obvious 
issues encountered with digital signature related transactions, and 
future validation of those transactions.  The problem is, if you are 
willing to honor signatures produced using certificates from an 
infrastructure that does support suspension, you wind up in the same 
boat.  It has been a topic of much debate.

Russ Housley wrote:
> riddled with difficulties, and those have been discussed many times over 
> the years.
> 
> argued that it was needed.  So, it was not deprecated.   You can look at 
> the archives for the recurring discussion.
> 
> Russ
> 
-- 

Regards,

Todd E. Johnson

---

From: "Todd E. Johnson" <[email-masked]>
Date: Wed, 23 Jan 2008 20:27:28 -0500

The U.S. Treasury PKI does not support suspension mainly due to obvious 
issues encountered with digital signature related transactions, and 
future validation of those transactions.

The problem is, if you are willing to honor signatures produced using 
certificates from an infrastructure that does support suspension, you 
wind up in the same boat.  It has been a topic of much debate.

-- 

Regards,

Todd E. Johnson

---

From: Scott Rea <[email-masked]>
Date: Wed, 23 Jan 2008 20:51:16 -0500

Yet the Shared Service Provider for both HHS and VA does support 
suspension and the Federal Common Policy Framework CP is ambivalent on 
this point - allowing each agency to choose
-Scott

---

From: "Todd E. Johnson" <[email-masked]>
Date: Wed, 23 Jan 2008 22:51:18 -0500

Not quite "ambivalent", since it is specific to prohibit suspension of 
CA certificates and leaves no binding requirements on the implementor 
for end entity certificates, but states that it is allowed.

I feel the ability to suspend technically, not the requirements of any 
particular policy, has compelled organizations to provide for a counter 
signing process when performing a digital signature transaction.  It is 
perceived that it helps to capture the validity of the signers 
certificate, at the time of signing, for future validation.  That is, if 
that organization ever choses to honor certificates from CAs whom 
support suspension.

Technical suspension is a completely useful tool in the world of 
authentication and authorization.

-- 

Regards,

Todd E. Johnson

---

From: Johannes Merkle <[email-masked]>
Date: Thu, 24 Jan 2008 09:55:33 +0100

Hi Massimiliano,

most signature laws I have seen so far had a quite clear
understanding of what they require. The problems arise from the
limitations in the technical implementations of their logical
requirements.

Johannes

-- 
Viele Grüße,
Johannes Merkle

---

From: Alfredo Esposito <[email-masked]>
Date: Thu, 24 Jan 2008 11:35:30 +0100

Hi Johannes

In my experience who write down the laws has often a poor understanding
of technical issues; therefore some words that have a very special
meaning in a technical specification are instead used in their general
meaning, causing a bit of confusion.

Suspension is one of these words, because a document signed during the
suspension should be "legally invalid" but there is no standard way of
checking a past CRL (i.e. verifying a signature at some time
t<<now). Better, there are some ways (ETSI specifications on
advanced signatures, putting the CRL in the PKCS#7 envelope) but none
is generally adopted.

On the other hand, the PKI standards were developed well in advance of
the legal concept of electronic signature, a concept that is still
unclear in Europe, in spite of the EU Directive of 8 years ago

Dino Esposito

Johannes Merkle wrote:

Hi Massimiliano,

Johannes

Hi all,

Later,
Max

Ignacio Alamillo wrote:

---

From: Johannes Merkle <[email-masked]>
Date: Thu, 24 Jan 2008 12:00:47 +0100

Hi Dino,

non-english speaking countries hardly use the term "suspension" in
their laws. Furthermore, the requirements imposed by the law usually
do not refer to any standards or technical solutions. This is
particularly true within the EU where electronic signatures do not
even need to deploy digital signatures.

Your appreciation regarding the source of the problems seems to
match mine: It's the limitation of technical standards to meet the
logical requirements of the legislation. (At least as long as SCVP
is not widely used.)

However, I disagree that a signature created while the certificate
was on hold must necessarily be considered invalid. This is a matter
of the certificate policy, and there are application scenarios for
suspension (reaction to unauthenticated revocation requests) where
such signatures could be regarded valid after reinstating of the
certificate. However, I do not advocate suspension as revocation and
potential certificate renewal is a better solution.

By the way: Here in Germany, suspension of qualified certificates is
considered inadmissable (at least by the supervising authority),
although there are no explicit requirements in the law and ordinance.

Johannes

Alfredo Esposito schrieb am 24.01.2008 11:35:
> checking a past CRL (i.e. verifying a signature at some time t<<now).
> Better, there are some ways (ETSI specifications on advanced signatures,
> putting the CRL in the PKCS#7 envelope) but none is generally adopted.

-- 
Viele Grüße,
Johannes Merkle

---

From: Alfredo Esposito <[email-masked]>
Date: Thu, 24 Jan 2008 12:09:45 +0100

Hi Johannes

In the Italian law the word adopted is "sospensione", the literal
translation of the english "suspension" and, sadly, the law explicitly
states that a document signed with a suspended or revoked certificate
is equivalent to a unsigned document. I agree with you that the
technical standards SHALL address this issue, but maybe IETF is not the
right forum

Ciao

Dino

Johannes Merkle wrote:

Hi Dino,

Johannes

Hi Johannes

Dino Esposito

Johannes Merkle wrote:

Hi Massimiliano,

Johannes

Hi all,

Later,
Max

Ignacio Alamillo wrote:

---

From: "Stevens, Frits" <[email-masked]>
Date: Thu, 24 Jan 2008 13:17:31 +0100

The IndenTrust community is using suspension with OCSP. Look at their
website, e.g.: http://www.identrust.com/pdf/IP-ICP_3.1a.pdf 
 
Regards,
Frits Stevens 

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
On Behalf Of Stephen Wilson
Sent: woensdag 23 januari 2008 02:50
To: [email-masked]
Subject: Certificate suspension

Thanks in advance.

Cheers,

Stephen Wilson
Managing Director
Lockstep

Phone +61 (0)414 488 851

www.lockstep.com.au
-------------------