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Amplifying side channels through performance degradation


Thomas Allan, Billy Bob Brumley, Katrina Falkner, Joop van de Pol and Yuval Yarom


University of Adelaide

Tampere University of Technology

University of Bristol


Interference between processes executing on shared hardware can be used to mount performance-degradation attacks. However, in most cases, such attacks offer little benefit for the adversary. In this paper, we demonstrate that software-based performance- degradation attacks can be used to amplify side-channel leaks, enabling the adversary to increase both the amount and the quality of information captured. We identify a new information leak in the OpenSSL implementation of the ECDSA digital signature algorithm, albeit seemingly unexploitable due to the limited granularity of previous trace procurement techniques. To overcome this imposing hurdle, we combine the information leak with a microarchitectural performance- degradation attack that can slow victims down by a factor of over 150. We demonstrate how this combination enables the amplification of a side-channel sufficiently to exploit this new information leak. Using the combined attack, an adversary can break a private key of the secp256k1 curve, used in the Bitcoin protocol, after observing only 6 signatures—a four-fold improvement over all previously described attacks.

BibTeX Entry

    month            = dec,
    paperurl         = {},
    booktitle        = {Annual Computer Security Applications Conference},
    author           = {Allan, Thomas and Brumley, Billy Bob and Falkner, Katrina and van de Pol, Joop and Yarom, Yuval},
    year             = {2016},
    pages            = {422--435},
    title            = {Amplifying Side Channels Through Performance Degradation},
    address          = {Los Angeles, CA, US}