Subject: Comments on (draft-ietf-pkix-logotypes-05.txt)

From: "David Cross" <[email-masked]>
Date: Sun, 22 Sep 2002 12:24:57 -0700

I hate to re-visit this late in the game, but...

I would like to strongly propose the following:

Section 3 - Support for the audio format should be optional for clients.
Again, this is a matter of practical implementation and I would like to
esnure that clients and compliant CA MAY support the audio file
logotype.

Section 4.1 - The indirect addressing scheme should be optional for
clients.  The indirect adressing schema MAY be supported by clients and
compliant CA.  I am afraid that unless pre-caching is performed by
clients, this option will not be practical to implement.

Section 7 - Security considerations.  Clients especially should be
cognizant that the URI of a logotype may point to an unusually large
binary object or contain executable code.  Clients MAY impose
constraints on the size or time to download a particular logotype.

Regards,
 
David B. Cross

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] 
Sent: Thursday, September 19, 2002 4:47 AM
Cc: [email-masked]
Subject: I-D ACTION:draft-ietf-pkix-logotypes-05.txt

A New Internet-Draft is available from the on-line Internet-Drafts
directories. This draft is a work item of the Public-Key Infrastructure
(X.509) Working Group of the IETF.

	Title		: Internet X.509 Public Key Infrastructure:
Logotypes in
                          X.509 certificates
	Author(s)	: S. Santesson, R. Housley, T. Freeman
	Filename	: draft-ietf-pkix-logotypes-05.txt
	Pages		: 19
	Date		: 2002-9-18
	
This document specifies a certificate extension for including logotypes
in public key certificates and attribute certificates. Please send
comments on this document to the [email-masked] mailing list.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-pkix-logotypes-05.txt

---

From: [email-masked] (Peter Gutmann)
Date: Thu, 26 Sep 2002 14:41:10 +1200 (NZST)

First, Bob Jueneman suggested MPEGs in certificates as a joke.  This is now
being standardised in the logotypes draft.

Then I suggested theme music in certificates as a joke.  This is now being
standardised in the logotypes draft.

Now, in an attempt to make the discussion even more surreal, I give you...

4.3. Scent logotypes

Alongside audio and video logotypes, it may be desirable for certificates to
carry scent logotypes in order to uniquely brand certificate holders in a
manner meaningful to relying parties.  For example, McDonalds may choose to
imbue their certificates with the aroma of fried beef patties and grilled
cheese, the National Park Service may choose the essence of pure Colorado
mountain air with just a hint of pine, and the NRA would use a heady mixture
of cordite and gun oil.

The new logotype would be implemented in the form of scratch-n-sniff
certificates, and will assist relying parties in making informed decisions as
to whether a particular certificate is trustworthy and relevant for its
intended usage.  Service providers and product vendors invest a lot of money
and resources into creating a strong relation between positive user
experiences and easily recognizable scents such as grilled beef, fresh air,
and cordite, allowing easy and familiar branding of certificates.

The scent logotype extension MUST have the following syntax:

      LogotypeScent ::= SEQUENCE {
         scentSubtype    IA5String, -- MIME scent subtype
         scent           OCTET STRING }

A MIME type is used to specify the format of the file containing the scent
logotype data.  The scent element contains the scratch-n-sniff scent logotype
associated with the certificate.

7.1. Security considerations

Implementors should be aware that there exists the potential for confusion
among relying parties when evaluating similar scent logotypes.  For example,
relying parties may not be able to meaningfully differentiate between the
logos for McDonalds and Burger King, or Hersheys and Nestle, or Sealord and
Penthouse.  Resolution of this issue lies outside the scope of this memo.

---

From: Franke Markus <[email-masked]>
Date: Fri, 27 Sep 2002 08:13:01 +0200

Basically we're very positive with your proposal. Unfortunately we 
observed some shortcomings in section 7.1 "Security considerations". 

As opposed to other known PKIX mechanisms, scent logotypes might be abused 
to cause immediate physical harm to the relying party. Especially allergic 
subjects might be affected by scent logotypes from e.g. an online flower 
store. Worst case, scent logotypes might also be abused for terroristic 
attack.

To fix those security issues we would suggest to add an additional third 
party harm assertion statement (TPHAS). This TPHAS should be protected by
cryptographic means to assure its authenticity and assure that the 
accompanying scent logotype will not impose undesired physical effects to 
its receiver.

In case we get some positive feedback we could provide a more extensive 
outline for the intended TPHAS syntax and processing. There is already 
some activity here to define this as a new XML language extension 
(TPHASML).

Regards,

Markus

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Thursday, September 26, 2002 4:41 AM
To: [email-masked]
Subject: Re: Comments on (draft-ietf-pkix-logotypes-05.txt) 

4.3. Scent logotypes

---

From: [email-masked] (Peter Gutmann)
Date: Fri, 27 Sep 2002 18:41:20 +1200 (NZST)

Franke Markus <[email-masked]> writes:

>accompanying scent logotype will not impose undesired physical effects to its
>receiver.

The addition of a reliance limit for damage caused by logotype certificate
extensions would be useful.  This would also cover malicious-MPEG-induced
epileptic seizures, MP3s with tones at the cranial resonant frequency of your
pets or designed to shatter the glass in your monitor, and other occurrences.

Peter.

---

From: "Hallam-Baker, Phillip" <[email-masked]>
Date: Fri, 27 Sep 2002 11:38:17 -0700

I remember the same arguments taking place when we were putting
multimedia into the Web.

People saw the need for inline images - popping up XV windows 
was not very convenient. But Inline movies and sound were generally
considered excessive (at the time the whole of CERN hung off a T1
and that was upmarket connectivity).

And yes people did try to raise scent in the attempt to make
a joke of a serious issue. 

However the arguments against smells are pretty compelling. First
despite trying nobody has developed an effective technology for 
recording or playback.

Second, polyester is a pretty awfull movie and even odourama 
does not save it.

		Phill

> Sent: Friday, September 27, 2002 2:41 AM
> To: [email-masked]; [email-masked]
> Subject: RE: Comments on (draft-ietf-pkix-logotypes-05.txt)
> 
> 
>

---

From: "Hamrick, Matt" <[email-masked]>
Date: Fri, 27 Sep 2002 17:10:09 -0400

Actually.... Joel White over at Tufts (http://www.neurosci.tufts.edu/White/)
is doing some interesting work in this field. I believe he's getting
research dollars to classify and encode scent information for automated
bomb-sniffing devices. I'll probably be chatting with him sometime over the
next couple of weeks, I'll ask him if he wants to write a draft standard for
scent encoding...

/etc
Matt H.

-----Original Message-----
From: Hallam-Baker, Phillip [mailto:[email-masked]]
Sent: Friday, September 27, 2002 2:38 PM
To: [email-masked]; [email-masked];
[email-masked]
Subject: RE: Comments on (draft-ietf-pkix-logotypes-05.txt)

		Phill