Using Memory Errors to Attack a Virtual Machine

gillus writes "A very cool scientific paper from Appel and Govindavajhala that explains how virtual machines like java or .Net can be exploited. How? Quite simple, bomb your DRAM chip with X-rays... or more simply with 50-watt spotlight, as the authors demonstrate. Definitively worth a read!"

Comments

Re:This just in!

[omnirealm]

Any encryption can still be broken through though brute force.

This is simply not true. One-time pads are 100% unbreakable, and they will always be unbreakable (at least mathematically speaking), no matter how sophisticated technology gets in the future. For those who are unfamiliar with the concept, a one-time pad is a cryptographically random string of 1's and 0's, which is at least of the same length of the message itself. Two parties have a secure channel in which to exchange these pads; for example, if Alice and Bob wish to use one-time pads, Alice can generate a list of 10,000 cryptographically random strings, put them in a suitcase that is handcuffed to her wrist, and deliver them to Bob in person. Bob and Alice then have a set of one-time pads that they can use for all future communication. Each time they encrypt a message with one of the pads, they discard the pad and never use it again. Because the pad is at least the length of any messages they might pass back and forth, there is no way to analyze the encrypted message for patterns. It is mathematically impossible. You could easily come up strings of 1's and 0's that would ``decrypt'' the message into anything, be it passages from the Bible, or Ogg Vorbis encoded music. You would have no idea which set of 1's and 0's produced the actual original message. This is truly unbreakable encryption on a mathematical level.

Most companies claiming that their encryption is ``unbreakable'' are using one-time pads; the problem is reduced to finding a secure channel of communications in which to transmit those pads. This is usually not a feasible assumption, which is why we all prefer using, for example, Diffie-Hellman key exchange, which depends on the difficulty of math involving discrete logarithms. The encryption we now use is breakable, but it is hard enough to break that it is generally considered secure.