Determinating timing channels in compute clouds

Abstract

Timing side-channels represent an insidious security challenge for cloud computing, because: (a) massive parallelism in the cloud makes timing channels pervasive and hard to control; (b) timing channels enable one customer to steal information from another without leaving a trail or raising alarms; (c) only the cloud provider can feasibly detect and report such attacks, but the provider's incentives are not to; and (d) resource partitioning schemes for timing channel control undermine statistical sharing efficiency, and, with it, the cloud computing business model. We propose a new approach to timing channel control, using provider-enforced deterministic execution instead of resource partitioning to eliminate timing channels within a shared cloud domain. Provider-enforced determinism prevents execution timing from affecting the results of a compute task, however large or parallel, ensuring that a task's outputs leak no timing information apart from explicit timing inputs and total compute duration. Experiments with a prototype OS for deterministic cloud computing suggest that such an approach may be practical and efficient. The OS supports deterministic versions of familiar APIs such as processes, threads, shared memory, and file systems, and runs coarse-grained parallel tasks as efficiently and scalably as current timing channel-ridden systems.

Cross-Tenant Side-Channel Attacks in PaaS Clouds

“…Various countermeasures to cache-based side channels (not necessarily Flush-Reload channels) have been proposed in IaaS cloud contexts [31,4,36,18,41,19,35]. However, none of these is applicable to our attacks.…”

Data Security, Privacy, Availability and Integrity in Cloud Computing: Issues and Current Solutions

“…In [27], there is an example of VM side-channel attack and how the attacker can infer some information about a victim. The timing side channel attack is one kind of VM side channel attacks [28]. This attack is based on determining the time needed by various computations.…”

“…This attack is based on determining the time needed by various computations. Determining this time can lead to leaking sensitive information such as described in [28]. This attack can help in leaking some sensitive information such as to the one who performs this computation or sometimes leaking information out of cloud provider itself.…”

Securing the Cloud: Threats, Attacks and Mitigation Techniques

“…Research on timing channels and their determination in cloud computing was conducted in [36]. This research proposed using provider-enforced deterministic execution as a replacement of resource partitioning to eliminate timing channels within a shared cloud domain.…”