Re: Ousourced Trust (was Re: Difference between TCPA-Hardware and a smart card and something else before

At 02:07 AM 12/28/2003 +1300, Peter Gutmann wrote:
> That's my big gripe with OCSP, it's compromised in almost every way in order
> to make it completely bug-compatible with CRLs.  It's really mostly an online
> CRL query protocol rather than any kind of status protocol (in other words a
> responder can give you an, uhh, "live" response from a week-old CRL via OCSP).
> A recent update to the protocol even removes the use of nonces, to make replay
> attacks possible.

in general, distributed cache/filesystem cache consistency algorithms 
aren't about trust or trust propogation but integrity and consistency.

I had done the initial distributed lock manager for ha/cmp. misc. past posts:
http://www.garlic.com/~lynn/2001.html#40 Disk drive behavior
http://www.garlic.com/~lynn/2001c.html#66 KI-10 vs. IBM at Rutgers
http://www.garlic.com/~lynn/2001e.html#2 Block oriented I/O over IP
http://www.garlic.com/~lynn/2001j.html#47 OT - Internet Explorer V6.0
http://www.garlic.com/~lynn/2001k.html#5 OT - Internet Explorer V6.0
http://www.garlic.com/~lynn/2002e.html#67 Blade architectures
http://www.garlic.com/~lynn/2002f.html#1 Blade architectures
http://www.garlic.com/~lynn/2002k.html#8 Avoiding JCL Space Abends
http://www.garlic.com/~lynn/2003i.html#70 A few Z990 Gee-Wiz stats

issue with certficates as cache entries ... is that they are purely r/o, 
static entries ... and the cache consistency protocols (either CRLs or 
OCSP) is purely with respect to whether the information is still fresh or 
not. however, I still contend that the primary design point for these 
deployed certificates is to allow relying-parties to perform offline 
operations when they wouldn't nominally have access to the real data (from 
which the certificate is derived).

the issue with the CRLs is that the are an electronic version of the paper 
booklets of invalid numbers in the credit card industry before online 
transactions. the issue is that the switch to a real online paradigm in the 
credit card industry in the '70s pretty much obsoleted the need for offline 
credentials (they retained the same form factor but added the magstripe for 
online transactions) and any infrastructure support for offline paradigm 
(like CRLs). OCSP appears to acquire all the infrastructure costs of doing 
online transaction while retaining all the disadvantages of CRL paradigm 
... i.e. undergo the costs of doing an actual online transaction w/o having 
any of the advantages of actually having done an online transaction. a 
trivial example is there is none of the benefits of aggregation (credit 
limit, fraud use patterns, etc) that comes with having a real online 
transaction.

the market niche for certificates are still the offline world (which is 
rapidly disappearing) or for extremely low value operations that don't 
justify the expense of online transaction. This issue in the later is 
two-fold 1) online transaction related costs continue to rapidly decline 
and 2) for low/no value operations it is difficult to justify the cost and 
complexity of PKI infrastructure.
--
Anne & Lynn Wheeler    http://www.garlic.com/~lynn/
Internet trivia 20th anv http://www.garlic.com/~lynn/rfcietff.htm
 

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