----- Original Message ----- From: "AARG! Anonymous" <remailer@aarg.net> [brief description of Document Revocation List]
Seth's scheme doesn't rely on TCPA/Palladium.
Actually it does, in order to make it valuable. Without a hardware assist, the attack works like this: Hack your software (which is in many ways almost trivial) to reveal it's private key. Watch the protocol. Decrypt protocol Grab decryption key use decryption key problem solved With hardware assist, trusted software, and a trusted execution environment it (doesn't) work like this: Hack you software. DOH!!!!! the software won't run revert back to the stored software. Hack the hardware (extremely difficult). Virtualize the hardware at a second layer, using the grabbed private key Hack the software Watch the protocol. Decrypt protocol Grab decryption key use decryption key Once the file is released the server revokes all trust in your client, effectively removing all files from your computer that you have not decrypted yet problem solved? only for valuable files Of course if you could find some way to disguise which source was hacked, things change. Now about the claim that MS Word would not have this "feature." It almost certainly would. The reason being that business customers are of particular interest to MS, since they supply a large portion of the money for Word (and everything else). Businesses would want to be able to configure their network in such a way that critical business information couldn't be leaked to the outside world. Of course this removes the advertising path of conveniently leaking carefully constructed documents to the world, but for many companies that is a trivial loss. Joe --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majordomo@wasabisystems.com