Visible to the public Ohm's Law in Data Centers: A Voltage Side Channel for Timing Power Attacks

TitleOhm's Law in Data Centers: A Voltage Side Channel for Timing Power Attacks
Publication TypeConference Paper
Year of Publication2018
AuthorsIslam, Mohammad A., Ren, Shaolei
Conference NameProceedings of the 2018 ACM SIGSAC Conference on Computer and Communications Security
Date PublishedJanuary 2018
PublisherACM
Conference LocationNew York, NY, USA
ISBN Number978-1-4503-5693-0
Keywordsattack surface, data center, Metrics, power attack, pubcrawl, resilience, Resiliency, Scalability, security, Time Frequency Analysis, voltage side channel
Abstract

Maliciously-injected power load, a.k.a. power attack, has recently surfaced as a new egregious attack vector for dangerously compromising the data center availability. This paper focuses on the emerging threat of power attacks in a multi-tenant colocation data center, an important type of data center where multiple tenants house their own servers and share the power distribution system. Concretely, we discover a novel physical side channel -- a voltage side channel -- which leaks the benign tenants' power usage information at runtime and helps an attacker precisely time its power attacks. The key idea we exploit is that, due to the Ohm's Law, the high-frequency switching operation (40\textasciitilde100kHz) of the power factor correction circuit universally built in today's server power supply units creates voltage ripples in the data center power lines. Importantly, without overlapping the grid voltage in the frequency domain, the voltage ripple signals can be easily sensed by the attacker to track the benign tenants' runtime power usage and precisely time its power attacks. We evaluate the timing accuracy of the voltage side channel in a real data center prototype, demonstrating that the attacker can extract benign tenants' power pattern with a great accuracy (correlation coefficient = 0.90+) and utilize 64% of all the attack opportunities without launching attacks randomly or consecutively. Finally, we highlight a few possible defense strategies and extend our study to more complex three-phase power distribution systems used in large multi-tenant data centers.

URLhttps://dl.acm.org/doi/10.1145/3243734.3243744
DOI10.1145/3243734.3243744
Citation Keyislam_ohms_2018