Heyman, Michael wrote:
Defense in depth can help against spoofing - this includes valid certificates, personalization (even if it is the less-than-optimal Citibank-like solution), PetName, etc. Man-in-the-middle is harder given that we have such a high false positive rate on our best weapon.
i would claim that SSL-like protocol with both countermeasure for MITM-attack and eavesdropping attacks should be adequate.
many of the current problems is that browsers and email clients have tended to added multiple layers of obfuscation around the URL process ... so it may be difficult for even experience users to realize what is happening
a semi-counter argument for defense-in-depth is KISS ... lots of complex layers tend to create all sorts of cracks for the attackers to get thru.
in theory, the KISS part of SSL's countermeasure for MITM-attack ... is does the URL you entered match the URL in the provided certificate. An attack is inducing a fraudulent URL to be entered for which the attackers have a valid certificates.
so some of the recent internet phishing countermeasures are trying to rely on clear, un-obfuscated indications recognizable by even naive users. however, the tend to be add-ons, non-integrated with existing countermeasures (like SSL MITM-attack countermeasures) and leave existing systemic vulnerabilities in place. When purely static data un-obfuscated recognizable indications are used independently of MITM countermeasures .... a MITM can create active channels between themselves and the end-user and themselves and the website and transparently pass information between the two end-points.
Rather than complex defense in depth ... all with cracks and vulnerabilities that attackers can wiggle around ... a better approach would be KISS solution that had integrated approach to existing systemic vulnerabilities. For instance, some sort of clear, un-obfuscated indications integrated with URL selection that can leverage the existing SSL MITM-attack countermeasures.
The downside of a KISS integrated solution that eliminates existing systemic problems (and avoids creating complex layers, each with their individual cracks that the attackers can wiggle thru) ... is that the only current special interest for such a solution seems to be the victims. Some sort of fix that allows naive users to relate and enter specific trusted URLs associated with specific tasks could fix many of the existing infrastructure vulnerabilities. The issue is what institutions have financial interest in designing, implementing, and marketing such a likely "free" add-on to existing mostly "free" based infrastructure. It appears to be much easier justify the design, implementation and marketing of a totally new feature that can be separately charge for.
some some topic drift ... one person's history of priced software: http://www.garlic.com/~lynn/2005g.html#51 http://www.garlic.com/~lynn/2005g.html#53 http://www.garlic.com/~lynn/2005g.html#54 http://www.garlic.com/~lynn/2005g.html#57 --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
