CDR: Re: Non-Repudiation in the Digital Environment (was Re: First Monday August 2000)

[Bob Jueneman]

Let's put this problem in perspective, and try to avoid the "chicken little, the sky is falling" syndrome.

It's quite unlikely that someone would come up with  "Eureka!" type of solution to factoring large numbers that would end up completely breaking RSA, or that some way would be found to completely break the integrity of SHA-1.

Instead, we would be much more likely to see a nibbling around the edges, and a gradually decreasing confidence in existing algorithms, with more than enough time to replace them.

In fact, we have already seen that.  MD2 is now deprecated, and MD5 is being pretty widely supplanted by SHA-1.  Likewise,  DES has been broken and people are recommending that triple-DES be used, and soon AES.  And OAEP is recommended to get around some hypothetical million-question attacks.

But the sky hasn't fallen, and the sun still comes up in the morning.

Even if some catastrophic weakness were somehow revealed that any high school kid could take advantage of with a single PC, there are still checks and balances.  The kid still has to have money in the bank to pay for the item, and all of the usual velocity checks, etc. that are used to combat fraud would still be in place and would work.  And good old-fashioned detective investigations and forensics would still be applicable.

Any good security system has defenses in depth, and is not subject to the balloon-popping problem.  

that doesn't mean that we shouldn't try to make systems be as perfect as possible.  But if they aren't (and they never are), that shouldn't be the end of the world as we know it.

Let's not invent a hypothetical Y2K problem.

Bob

Robert R. Jueneman
Security Architect
Novell, Inc.  -- the leading provider of Net services software.



>>> Tony Bartoletti <azb at llnl.gov> 10/19/00 04:09PM >>>
At 04:58 PM 10/19/00 -0400, Arnold G. Reinhold wrote:

>>Yes, that is why Tony's remark was somewhat tongue-in-cheek and used
>>"solid mathematical foundations" within quotes.
>
>Eye twinkle doesn't come across in e-mail, I'm afraid. My apologies to 
>Tony. This is obviously one of my hot buttons.

No problem.  I often employ a quoted "x" to convey "so-called x", a 
shortcut that
can lead to misunderstandings.


>>>It is all hypothesis and empirical argument. A lone
>>>mathematician working in his attic could come up with an algorithm
>>>that would blow some or all of the existing systems out of the water.
>>>Who get to cover that financial risk?
>>
>>The buyer. CAs (read Verisign's CPS or any CA's CPS, or bank contracts
>>and -- above all -- see the US UCC) are not responsible for producing correct
>>results but just for using correct methods. Where "correct methods" are
>>what others consider correct -- even if they are proved wrong later on
>>by a one mathematician working in his attic.
>
>I'm not sure those contracts would stand up in court if there were massive 
>public losses due to a collapse of the PKI. (Anyway CA CPS's stretch to 
>notion of a "mutual agreement" pretty far. I purchase a $10 cert and am 
>bound by over 100 pages of gobbldygook that only a handful of people on 
>the planet can be expected to fully understand?)
>
>But I am less concerned with CA legal liability then with who is left 
>holding the bag when a massive subversion of the banking system is 
>perpetrated, and how big that could be.

I'll wager the taxpayer/consumer will foot the bill, one way or another.

Derivative to the Second Law of Thermodynamics, it is easier to destroy wealth
than it is to create it.  So, on average, work/energy is required to create
or recreate wealth.  The collapse of a future global PKI, or of the integrity
of banking transactions, would represent a huge shift from order into chaos,
a decoherence of identities and orderliness amounting to a huge destruction
of wealth.  Recovery thus will require the recreation of wealth, in one form
or another.  This will require a correspondingly huge input of work.  So, who
does most of the work, in general?  You know the answer ;)

___tony___


Tony Bartoletti 925-422-3881 <azb at llnl.gov>
Information Operations, Warfare and Assurance Center
Lawrence Livermore National Laboratory
Livermore, CA 94551-9900