So: If you can't trust your path to your own file system, what can you trust? (And this is without even talking about things like firmware upgrades and BIOS patches and all sorts of other potential approaches.) Can we do no better than simply assume the local workstation file system can be trusted?
Nah, it's not as bad as all that. There's fixes to all of this, they're well known, and actually in place at some places. Because it's such a pain having good security on all of the machines most sites choose to have really good security on a firewall to keep the bad guys out, and through policy, isolation, and less stringent security measures protect the machines inside the firewall. That's not to say that everyone with a firewall has good security, far from it. It's also not to say that everyone without a firewall is vulnerable, they're not...I know folks with all of their machines buttoned up tight. It's possible to close most categories of holes, and to detect intrusions in progress. You say you're worried about the system being corrupted so that you can't trust calls to the OS. Some attacks do work this way, but you can prevent the attack via a combination of good security and good practices. And yes, secure authentication and transmission of data makes everything much simpler;) Without it you have to essentially pull up the drawbridge and trust no one outside the moat, since there's no way of knowing if anyone, or any host is who or what they say they are. If anyone wants more specific information about how to protect from various attacks I can help or give you references to the literature, but I won't go into it here since I expect that most anyone you'd find on cypher- punks knows all this at least in outline already. Patrick _______________________________________________________________________ / These opinions are mine, and not Verity's (except by coincidence;). \ | (\ | | Patrick J. Horgan Verity Inc. \\ Have | | patrick@verity.com 1550 Plymouth Street \\ _ Sword | | Phone : (415)960-7600 Mountain View \\/ Will | | FAX : (415)960-7750 California 94303 _/\\ Travel | \___________________________________________________________\)__________/