RE: Transitive Trust: 40 million credit cards hack'd

["Bill Royds" <broyds () rogers com>]

The problem is that people have never truly analysed trust in a systematic
mathematical way.
Trust is assumed to be a transitive property when it obviously is not. If Alice
Trusts Bob and Bob trusts Charles it is not true that Alice should or would
trust Charles. Trust is not even transitive.   We seem to see it as a simple
relationship when it is not even well understood at all. There has recently been
some theoretical work on trust algebras (see
http://security.polito.it/cms2003/Program/Roessler13/1Roessler.pdf or
http://security.dstc.edu.au/staff/ajosang/papers/algcert.pdf for example) but
little of it has filtered into actual practice.  Yet we are building whole
financial edifices on completely flawed understanding of how to use distributed
trust. We need to at least develop some systems that do it right so developers
have some way of learning how to create viable systems that can have distributed
security.


-----Original Message-----
From: firewall-wizards-admin () honor icsalabs com
[mailto:firewall-wizards-admin () honor icsalabs com] On Behalf Of George Capehart
Sent: Saturday, June 18, 2005 6:56 PM
To: Marcus J. Ranum
Cc: firewall-wizards () honor icsalabs com
Subject: Re: [fw-wiz] Transitive Trust: 40 million credit cards hack'd

Heh.  Just wait until Web services get widely deployed . . .  No one is
even thinking multiple trust boundaries yet . . . much less how to make
systems operate across them.  All the lessons we learned from the DCE,
CORBA, Kerberos, SESAME, et al. (about what happens when one crosses
trust boundaries (/*within* the organization*/) are about to be learned
all over again, but with a much larger population . . . It's going to be
a mess . . . And there will be no Plan B because no one has a clue what
they're getting into . . .  I gave a talk at OWASP last year that
touched on this and, out of an audience of a couple of hundred people,
only a handful showed that they'd understood the magnitude of the problem.

Cheers,

/g

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