Channel Attacks

This excellent page (along with a really good paper) made me discover the concept of channel attack. Basically, a channel attack consists in discovering something about data being processed by measuring the side effect of processing them, such as latency or even power consumption. Here's an other paper on channel attacks. Fascinating stuff as they seem to be really hard to close (they rely on the nature of the data processing that is being performed.)

The page that triggered the post speaks of channel attacks in the context of hyperthreading able CPUs. Recommendation to limit exposure are numerous:

• HT aware cache sharing prevention
• OS level prevention of execution of applications of different privilege level on the same core.
• Crypto library should be redesigned to prevent channel attacks

Now here's something about an instance of side channel attack, and the process of a side channel attack is presented here.