A coda on today's voluminous discussion of X.509, browser security, etc. It is important to remember what we're trying to defend against. As many of us have learned through bitter experience, the costs and benefits of security systems we deploy are the important part. No one needs perfect security in the face of no attackers at all, and even if attackers are numerous, if a system has low enough failure/fraud rates, no one will complain much.
The problem is that the system we've built to date is, in fact, yielding pretty high fraud rates. Attacking people is a full time profitable business for a lot of people, not a rare sort of thing. Stolen credentials are sold in the market for very low prices because there is a glut of them. Yes, the majority of online transactions are trouble free, but a shocking fraction of them are not, and the majority of people I know have had a card stolen at least once online. Things like bank account credential phishing are not only possible but prevalent. All this may get worse. The cost is a large fraction of the fees we all end up paying, directly and indirectly, to do business. What we would like is to get from the situation we are in now (which reminds me in certain ways of the days of analog cellphone service where cloning was trivial) to a situation where fraud still happens but is much more difficult to pull off. (Certainly phone fraud still happens, but it is no longer anything like it was in the NAMPS days and the cost is manageably low.) This would also have the benefit of radically reducing the number of people who can make a living as professional attackers, which would have all sorts of salutary effects. To lower the fraud rate by significant margins, I think we'll need to make some serious changes in the security systems we deploy. Logging in to your bank's web site using a password protected by an SSL session requires that too many things all go right and that the user pay attention to whether they have all gone right. We need simpler systems where, if the user is not paying attention, nothing much bad can happen to them anyway. No system can be perfect, but we could do a lot better than we are doing now. I think this is achievable in theory. Whether it can happen in practice, I have my doubts, though we can but try. Perry -- Perry E. Metzger pe...@piermont.com --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majord...@metzdowd.com