4 ms·
For Linux there is TRESOR (http://www1.informatik.uni-erlangen.de/tresor http://www1.informatik.uni-erlangen.de/tresor). It uses CPU registers, which can preve
by aryastark 13y ago
For Linux there is TRESOR (http://www1.informatik.uni-erlangen.de/tresor http://www1.informatik.uni-erlangen.de/tresor). It uses CPU registers, which can prevent this sort of attack. However, you're limited to one encrypted drive with this method.
- RexRollman 13y agoModern CPUs have a lot of cache these days. Couldn't the keys be store there are well (assuming the threat is just the removal and reading of RAM)?
- sweis 13y agoHi. L3 caches are indeed huge these days. For example, the latest Mac Pros are shipping with 30MB L3 caches. You can do a lot with that space. My company PrivateCore runs an entire Linux/KVM stack within the L3 cache, then fully encrypts main memory. Someone physically acquiring memory would only obtain plaintext. Note that a software compromise could still read memory. That's one reason why it's necessary to fully attest a system before provisioning it with any keys or passwords. Here's a CanSecWest talk with more details: http://cansecwest.com/slides/2013/PrivateCore%20CSW%202013.pdf http://cansecwest.com/slides/2013/PrivateCore%20CSW%202013.p...
- RexRollman 13y agoThanks!
- jevinskie 13y agoVery cool! How small of a cache can you work in?
- informatimago 13y agoYou mean cypher text. Plain text is clear text is unencrypted.
- deleted 13y ago[deleted]
- keeperofdakeys 13y agoThe caches are designed to be transparent, so you can't store data in them separately. Not to mention that your program could be interrupted at any point, so the OS would have to backup this data into ram (like it does registers).
- sweis 13y agoTRESOR only helps against passive attacks since since the code is still exposed in memory. Active attacks that modify memory can easily circumvent it.
- aryastark 13y agoNot sure what you mean. TRESOR prevents cold boot attacks. If your Linux OS is compromised, TRESOR wouldn't help you anyway. But that's not the point of it, either.
- sweis 13y agoYes, TRESOR can help against cold boot attacks, which are passive and read-only. Several physical attack vectors can modify the contents of memory, thus compromise the software stack and divulge keys kept in registers or cache. Our approach at PrivateCore is to fully encrypt main memory with an authenticated cipher mode and keep the software stack pinned in cache. An attacker able to physically modify memory can only conduct a DoS attack by inserting junk data.