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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: BGP Security and PKI Hierarchies (was: Re: Wifi Security)
In message <[email protected]>, Randy Bush writes: >>>> I believe a web of trust can be operationally feasible only if the web >>>> is more like a forest - if there are several well known examples of >>>> "tops" to the web. Otherwise, you have to be storing a plethora of >>>> different signers' certificates to be able to validate all the >>>> institution's certificates that come in. >>> >>> you need those certs to verify the live data anyway >>> >> Right. The real issue is the trust determination -- how do you know >> that the certificate corresponds to something resembling reality >> (whatever that is)? > >for how many years have i been asking you and your evil-minded cert >designing friends for a pgp-like web of trust cert that could be >used for just this application? > Actually, I don't do certs; it's my evil-minded friends... That said, I think the problem is that we need an algebra of trust that will let a program, not a human, decide whether or not to trust a certficate. You don't want to accept something if it's a twisty loop of subsidiaries or allied evil ASs vouching for each other. OTOH, there are some situations where we know that absolute trust is indicated -- say, 701 signing 702's certificate, or an upstream signing the address certificate for a customer. And it's not just honesty, it's competence you're assessing -- we've all seen problems when major ISPs didn't get their filters straight. Furthermore, given that a trust algebra may yield a trust value, rather than a simple 0/1, is it reasonable to use that assessment as a BGP preference selector? That would tie the security very deeply -- too deeply? -- into BGP's guts. --Steven M. Bellovin, http://www.cs.columbia.edu/~smb
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