Subject: Re: draft-ietf-pkix-warranty-extn-01.txt

From: Denis Pinkas <[email-masked]>
Date: Tue, 03 Dec 2002 13:58:32 +0100

Alice,

> Anders,

> I respectfully disagree.  

I support the position from Anders. He is right. The topic is liability, not 
warranty.

> You're right that a CA is not like GM or Ford, but
> why can a CA not offer a warranty?  Perhaps what is missing here is a
> definition of warranty, which, in insurance terms, is attestation of the
> intent to provide compensation for harm incurred by using a certificate
> (that is, a certificate that is faulty in some way).  Warranty is not the
> same as liability; warranty is something that the CA can control, whereas it
> cannot completely control liability.  

But we are exactly in a case where the CA cannot control all the damages !

So a liability cap has to be applied. Clients cannot get a warranty since it 
is unsure which amount of money they will ever get for it.

 > The CA (or indeed any product- or
> service-offering company) may try to limit its liability, but regardless of
> this attempt, the extent of liability will ultimately be decided by the
> courts.

This is not want people are looking for: they want to avoid Courts !

When there is a warranty it must be applied and it is not dependent of other 
events, like the number of plaintiffs for the same "error" from the CA.

You are talking about liability, not warranty.

Denis

> You seem to be defining warranty rather narrowly, as replacement or refund
> in the event of an inherent flaw.
> 
> Similarly, it seems to me that I define risk management more broadly than
> you suggest.  Every time an RP enters into a transaction, or considers doing
> so, the RP makes a risk management decision.  This can be quite a natural
> and intuitive process, or it can be explicitly defined; either way, the
> decision is made, and it will be based on more or less information.  The
> more information an RP has, the more informed the risk management decision
> will be.  If a certificate contains information pertaining to the existence
> of compensation in the event of harm, then the RP has more information on
> which to make a risk decision.  Armed with this information, as well as
> information about other factors of the transaction, such as value,
> sensitivity of information, parties to the transaction (e.g., known or
> unknown), etc., the RP's risk is reduced by virtue of knowing more about all
> of the risk factors - including warranty.  If there is a TTP involved, this
> again becomes a factor in the RP's risk management decision.
> 
> My 2 Canadian cents again.
> 
> Alice
> 
> 
> 
> Alice Sturgeon
> Chair
> Canadian Advisory Committee - Information Technology Security
> ISO/IEC JTC1 SC 27
> and
> System Policy Architect
> SPYRUS
> Phone:     613-232-2350
> Cell:         613-291-0331
> 
> 
> 
> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]]On
> Behalf Of Anders Rundgren
> Sent: November 28, 2002 12:29 PM
> To: [email-masked]
> Subject: Re: draft-ietf-pkix-warranty-extn-01.txt
> 
> 
> Hi,
> 
> After reading this draft I believe the name "warranty" is a bit
> misleading.  It is, (or should IMHO at least be), focused on
> CA liability issues as a CA cannot be compared to a car maker,
> as the only the latter will repair or replace their products in case
> of faults.  Well, to get a "replacement" certificate would be the
> equivalence but that is sort of taken for granted anyway. :-)
> 
>                   CA-liability-extn
> 
> seems to be closer to what we are actually dealing with.
> 
> I would also be very cautious about RP "risk management"
> because that's rather fictional.  The risk you take by accepting
> an unknown[*] business partner is likely to be magnitudes bigger
> than accepting their certificates.   If the CA is unknown as well
> you have nothing to build PKI trust on either.
> 
> For TTP CAs OTOH, "risk management" with respect to
> client-certificates is a part of their daily bread.
> 
> Just my 2 öres
> 
> Anders
> 
> *] with respect to performance, trustworthiness, credibility etc.
>

---

From: Russ Housley <[email-masked]>
Date: Tue, 03 Dec 2002 10:37:17 -0500

Denis & Anders:

The topic is warranty.  If the replying party is somehow wronged by the 
incorrect content of a certificate, then the replying party can make a 
claim against the warranty.  The extension provides information about this 
warranty.

If the warranty offered by the CA is inadequate for a particular 
transaction, then the relying party can obtain it own insurance or walk 
away from the transaction.  If the relying party does seek its own 
insurance, it will likely cover more than just the subscriber certificate, 
but that is a whole new topic, and it is beyond the scope of the charter of 
the PKIX WG.

Russ

At 01:58 PM 12/3/2002 +0100, Denis Pinkas wrote:

>Alice,
>
>>Anders,
>
>>I respectfully disagree.
>
>I support the position from Anders. He is right. The topic is liability, 
>not warranty.
>
>So a liability cap has to be applied. Clients cannot get a warranty since 
>it is unsure which amount of money they will ever get for it.
>
>When there is a warranty it must be applied and it is not dependent of 
>other events, like the number of plaintiffs for the same "error" from the CA.
>

---

From: Denis Pinkas <[email-masked]>
Date: Tue, 03 Dec 2002 17:05:18 +0100

Russ,

> The topic is warranty.  

I respectfully disagree. The topic is liability, more exactly liability 
limitations.

There is no warranty that a plaintiff will ever get some money, but some 
guarantee that it will never get more than some amount of money. IN 
addition, the conditions to get it are very fuzzy.

> If the replying party is somehow wronged by the 
> claim against the warranty.  The extension provides information about 
> this warranty.

It is a claim against the *liability* of the CA.

> transaction, 

The CA is ignorant of transactions, so it cannot offer a warranty for a 
particular transaction !

> then the relying party can obtain it own insurance or walk 
> away from the transaction.  

No. The relying party can walk away from the CA. :-)

Please take a look at documents like ETSI TS 102 042 or ETSI TS 102 456:

    - TS 102 042 (Policy requirements for certification authorities
                 issuing public key certificates)

    - TS 101 456 (Policy requirement for certification authorities
                  issuing qualified certificates)

They are both on certification policies and include a section on liability, 
not on any kind of warranty.

Denis

> If the relying party does seek its own 
> insurance, it will likely cover more than just the subscriber 
> certificate, but that is a whole new topic, and it is beyond the scope 
> of the charter of the PKIX WG.
> 
> Russ
> 
>> I support the position from Anders. He is right. The topic is 
>> liability, not warranty.
>>
>> So a liability cap has to be applied. Clients cannot get a warranty 
>> since it is unsure which amount of money they will ever get for it.
>>

---

From: Russ Housley <[email-masked]>
Date: Tue, 03 Dec 2002 11:55:43 -0500

Denis:

>guarantee that it will never get more than some amount of money.

If you buy a radio, and it does not work, the warranty will replace the radio.

If you rely on a certificate with this extension, and the information in 
the certificate is wrong, the CA will honor claims under the 
warranty.  Just asserting that the certificate is wrong should not be 
sufficient; however, if it is wrong, then the claim should be processed.

Russ

---

From: "Alice Sturgeon" <[email-masked]>
Date: Tue, 3 Dec 2002 18:19:55 -0500

Denis and Anders,
I agree with Russ.  This I-D concerns the possible provision of warranty.
There is a significant difference in law (in all countries) between
liability and warranty, and we are not talking about liability.  Warranty is
a positive offering by a party to another party, where the first party
warrants that its product or service will perform as it is expected to, for
its intended purpose, and if it does not due to some flaw, the first party
is committing to compensate the second party.  Liability concerns the
examination in law by a third party of the first party's responsibility to
the second party, and if the third party finds that the first party did not
deliver a product or service as the first party indicated it would, then the
third party assesses a measure of compensation from the first party to the
second party.  Warranty has nothing to do with liability under the law.
This I-D is not intended to be a legal document, or a document about law; it
is intended to be a technical specification to address the offering of a
warranty from the first party to the second party, in this case, a CA to a
relying party.  In this, the I-D is not at all about liability.
BTW, to return to Denis' argument, one point about warranty is that it is a
way to avoid the courts.  And the offering of a warranty is indeed something
that a CA can control.  And, yes, any relying party that has been offered
the warranty will be compensated under it in the event of harm, and it could
be one or many RPs (but they will not be "plaintiffs").

Alice

Alice Sturgeon
Chair

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]On
Behalf Of Russ Housley
Sent: December 3, 2002 10:37 AM
To: Denis Pinkas; Anders Rundgren
Cc: [email-masked]; [email-masked]
Subject: Re: draft-ietf-pkix-warranty-extn-01.txt

Denis & Anders:

Russ

---

From: Denis Pinkas <[email-masked]>
Date: Wed, 04 Dec 2002 09:35:17 +0100

Alice,

> I agree with Russ.  

I already noticed it. :-)

> This I-D concerns the possible provision of warranty.

> is committing to compensate the second party.  

In practice, warranties are not higher than the price of the product or of 
the service. If the product or service is defective, then the party repairs 
it or replaces it. There is no compensation for the number of days where the 
product or the service could not be used, nor for the business dammages that 
occur because the product or the service was defective. See some licensing 
conditions from software vendors.

> Liability concerns the

The basic purpose is precisely a limitation of compensation, in case the 
third party finds out a major hidden defect in the product or service. We 
are in that case.

> relying party.  In this, the I-D is not at all about liability.

Once again a danger of this document is to provide a fake warranty and to 
undermine the confidence people may have in certificates.

> that a CA can control.  

I would like your statement to be true, but it is not. The CA cannot control 
the number of misuses of a certificate that was not correctly handled by the 
CA, nor the amount of the transactions done by a certificate.

If you make the sum of an unknown number of transactions multiplied by an 
unknown (even limited) amount for each transaction, the end-result is 
unknown. Since this may occur not for only one certificate, but for an 
unknown number of certificates, you have to multiply the previous unknown 
result by that unknown number. All this is beyond control of the CA.

If we had an on-line service registering each transaction and its amount 
then a warranty could be given, but this is not what the draft is about.

 > And, yes, any relying party that has been offered

The compensation is unpredictable since it depends of the number of 
"plaintiffs". With a real warranty, a RP will know in advance what you will 
get, *irrespective of the number of other RPs*.

Now, you will not be surprised of my conclusion:
On this topic, I agree with Anders.

I suggest that you issue: draft-ietf-pkix-liability-extn-00.txt

:-)

Denis

>>>same as liability; warranty is something that the CA can control, whereas
>>
> it
> 
>>>service-offering company) may try to limit its liability, but regardless
>>
> of
> 
>>other events, like the number of plaintiffs for the same "error" from the
> 
> CA.
> 
>>>you suggest.  Every time an RP enters into a transaction, or considers
>>
> doing
> 
>>>will be.  If a certificate contains information pertaining to the
>>
> existence
> 
>>>unknown), etc., the RP's risk is reduced by virtue of knowing more about
>>
> all
> 
>>>of the risk factors - including warranty.  If there is a TTP involved,
>>
> this
>

---

From: "Anders Rundgren" <[email-masked]>
Date: Wed, 4 Dec 2002 09:32:03 +0100

Alice,
The ID do mention the word liability in several places.

Anyway, my (and probably Denis' as well) main concern is that liability
addresses a real and often cited problem for CAs.  *If* and only if, a
liability-extension could reduce or even eliminate the need for specific
agreements (that typically only say that the CA has none or very limited
liability), between TTP CAs and RPs, such an extension could be *very*
beneficial.

BTW, could you elaborate on the value of warranty (or liability)
extensions for closed PKIs  where the CA and RPs belong to the
same community or organization, where RPs have no real
alternative but to trust the received certificate.

Anders

----- Original Message -----
From: "Alice Sturgeon" <[email-masked]>
To: "Russ Housley" <[email-masked]>; "Denis Pinkas" <[email-masked]>; "Anders Rundgren" <[email-masked]>
Cc: <[email-masked]>
Sent: Wednesday, December 04, 2002 00:19
Subject: RE: draft-ietf-pkix-warranty-extn-01.txt

Denis and Anders,

Alice

Alice Sturgeon
Chair

-----Original Message-----

Denis & Anders:

Russ

it
of
CA.
doing
existence
all
this

---

From: Andreas Mitrakas <[email-masked]>
Date: Thu, 05 Dec 2002 18:43:51 +0100

Let me just jump into this discussion for a minute to just say that the two ETSI
documents that Denis has mentioned indeed refer to liability but for a reason,
being their relevance to the liability rules of the EU Directive on electronic
signatures. This Directive lays out specific liability conditions for CSP
operations.

With regard to warranties, perhaps it makes sense to give some guidance on CA
related risks and distinguish them from transaction risks. The CA risks, for which
a warranty can be offered include for example the correctness of the data on the
certificate, the integrity of its private key etc. When the subscriber purchases a
general purpose certificate, the CA rightfully limits the purpose for which this
certificate can be used, e.g. don't use a 10 Euro general purpose certificate to
run operations in a nuclear facility, for example. The transaction risks associate
with the transacting parties, or the provider of a transaction platform, for
example. Trying to link the certificate with hte purpose it is used makes no sense
-- although it has previously been suggested by the EU Parliament in a little
commnetary of the EU Directive they issued a few years back.

andreas mitrakas
Ubizen

---

From: "Anders Rundgren" <[email-masked]>
Date: Fri, 6 Dec 2002 09:55:11 +0100

Andreas,
If we are dealing with consequences of a CA error rather than
replacements of defective products, what would the _practical_
difference for RPs and subscribers be, between a liability limit and
a warranty?

If the difference is only to be found in the agreements, I believe
we are in fact dealing with a single issue rather than two, as even
liability agreements may differ in context.

cheers,
Anders

----- Original Message -----
From: "Andreas Mitrakas" <[email-masked]>
To: "Denis Pinkas" <[email-masked]>
Cc: <[email-masked]>; "Russ Housley" <[email-masked]>; "Anders Rundgren" <[email-masked]>;
<[email-masked]>
Sent: Thursday, December 05, 2002 18:43
Subject: Re: draft-ietf-pkix-warranty-extn-01.txt

andreas mitrakas
Ubizen

---

From: Andreas Mitrakas <[email-masked]>
Date: Fri, 06 Dec 2002 12:16:00 +0100

Anders,

from an RP perspective this matter touches upon the statutory liability level as for example it is addresse in art 6
of the EU Directive. The liability of the CA for publishing a certificate featuring erroneous data, for example,
would be detrmined in court. The CA however, has the right to set a limit to the value of the transactions a specific
cert can be used for. This does not mean that RPs cannot perform transactions in excess to such cap, but only that
they act at their own risk.

A warranty --as I believe Alice said yesterday -- is a positive offer by the CA to cover transactions up to a certain
limit. Such warranty, if accepted by RPs would limit any future claims, with the exception of any statutory liability
the CA may incur. If there is a warranty and something goes wrong the RP can have a direct claim from the CA. A
warranty makes sense since the potential risk for a CA is enormous, if you consider the amount and value of the
transactions, a certificate can be used for. In support of a warranty the CA might seek an insurance policy, but this
probably gets beyond the point.

On a certificate an RP possibly needs an indication of a cap -- this could be just a numeric field. Warranty terms
can be part of the policy.

I hope this helps,

andreas