Access member only content, take part in discussions with comments on blogs, news and reviews and receive all the latest security industry news directly to your inbox. Join now for free.
Processing registration... Please wait.
This process can take up to a minute to complete.
A confirmation email has been sent to your email address - SUPPLIED EMAIL HERE. Please click on the link in the email to verify your email address. You need to verify your email before you can start posting.
If you do not receive your confirmation email within the next few minutes, it may be because the email has been captured by a junk mail filter. Please ensure you add the domain @scmagazine.com.au to your white-listed senders.
Researchers have demonstrated a controlled attack in which private keys can be stolen from a virtualised machine.
The side-channel cryptographic attack was thought to be the first of its kind and could have serious consequences for cloud computing environments where an attacker is co-resident to a victim.
It was demonstrated in a paper (pdf) by researchers from the universities of North Carolina and Wisconsin along with security outfit RSA on a Xen-based virtualisation platform that replicated public cloud infrastructure.
RSA laboratories director Dr Ari Juels said while the attacks were made in a lab, there was “no reason to think that any public virtualised infrastructure is immune” from the attacks.
“The takeaway is this: VMs (virtualised machines) running highly sensitive workloads should not be placed on the same hosts as potentially untrustworthy VMs,” Juels said.
The attacks targeted a vulnerability in the cryptographic package libgcrypt used by GnuPG, which lacked defences against side-channel attacks.
Side-channel leaks were present in some crypto installations as a result of resource exposure.
“In our experiments, an attacker VM targets a co-resident victim VM running Gnu Privacy Guard,” Juels said.
“The attacker VM is able to steal the victim VM’s full private (ElGamal) key. In other words, the attack results in complete compromise of one form of encryption in GnuPG.”
The success of the attack in gaining the keys rendered obsolete existing beliefs that virtualisation, through the use of distinct operating systems, provided effective isolation and therefore security.
It did this by targeting shared hardware resources, specifically the L1 instruction cache, which revealed enough information based on alternate process execution between the target and attacker to build a crypto key.
Importantly, the access-driven side-channel attacks overcame challenges including hypervisor noise, core migration, and the “difficulty of preempting the victim with sufficient frequency to extract fine-grained information”.
While the attacks required a target and attacker to be co-resident on a single machine, earlier research (pdf) had shown it is possible to locate clients within cloud infrastructure.
Copyright © SC Magazine, Australia
To begin commenting right away, you can log in below or register an account if you don't yet have one. Please read our guidelines on commenting. Offending posts will be removed and your access may be suspended. Abusive or obscene language will not be tolerated. The comments below do not necessarily reflect the views or opinions of SC Magazine, Haymarket Media or its employees.