TY - GEN
T1 - A Formal Analysis of Timing Channel Security via Bucketing
AU - Terauchi, Tachio
AU - Antonopoulos, Timos
N1 - Funding Information:
Acknowledgements. We thank the anonymous reviewers for useful comments. This work was supported by JSPS KAKENHI Grant Numbers 17H01720 and 18K19787, JSPS Core-to-Core Program, A.Advanced Research Networks, JSPS Bilateral Collaboration Research, and Office of Naval Research (ONR) award #N00014-17-1-2787.
Publisher Copyright:
© The Author(s) 2019.
PY - 2019
Y1 - 2019
N2 - This paper investigates the effect of bucketing in security against timing channel attacks. Bucketing is a technique proposed to mitigate timing-channel attacks by restricting a system’s outputs to only occur at designated time intervals, and has the effect of reducing the possible timing-channel observations to a small number of possibilities. However, there is little formal analysis on when and to what degree bucketing is effective against timing-channel attacks. In this paper, we show that bucketing is in general insufficient to ensure security. Then, we present two conditions that can be used to ensure security of systems against adaptive timing channel attacks. The first is a general condition that ensures that the security of a system decreases only by a limited degree by allowing timing-channel observations, whereas the second condition ensures that the system would satisfy the first condition when bucketing is applied and hence becomes secure against timing-channel attacks. A main benefit of the conditions is that they allow separation of concerns whereby the security of the regular channel can be proven independently of concerns of side-channel information leakage, and certain conditions are placed on the side channel to guarantee the security of the whole system. Further, we show that the bucketing technique can be applied compositionally in conjunction with the constant-time-implementation technique to increase their applicability. While we instantiate our contributions to timing channel and bucketing, many of the results are actually quite general and are applicable to any side channels and techniques that reduce the number of possible observations on the channel.
AB - This paper investigates the effect of bucketing in security against timing channel attacks. Bucketing is a technique proposed to mitigate timing-channel attacks by restricting a system’s outputs to only occur at designated time intervals, and has the effect of reducing the possible timing-channel observations to a small number of possibilities. However, there is little formal analysis on when and to what degree bucketing is effective against timing-channel attacks. In this paper, we show that bucketing is in general insufficient to ensure security. Then, we present two conditions that can be used to ensure security of systems against adaptive timing channel attacks. The first is a general condition that ensures that the security of a system decreases only by a limited degree by allowing timing-channel observations, whereas the second condition ensures that the system would satisfy the first condition when bucketing is applied and hence becomes secure against timing-channel attacks. A main benefit of the conditions is that they allow separation of concerns whereby the security of the regular channel can be proven independently of concerns of side-channel information leakage, and certain conditions are placed on the side channel to guarantee the security of the whole system. Further, we show that the bucketing technique can be applied compositionally in conjunction with the constant-time-implementation technique to increase their applicability. While we instantiate our contributions to timing channel and bucketing, many of the results are actually quite general and are applicable to any side channels and techniques that reduce the number of possible observations on the channel.
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U2 - 10.1007/978-3-030-17138-4_2
DO - 10.1007/978-3-030-17138-4_2
M3 - Conference contribution
AN - SCOPUS:85064920904
SN - 9783030171377
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 29
EP - 50
BT - Principles of Security and Trust - 8th International Conference, POST 2019, Held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2019, Proceedings
A2 - Nielson, Flemming
A2 - Sands, David
PB - Springer Verlag
T2 - 8th International Conference on Principles of Security and Trust, POST 2019 Held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2019
Y2 - 6 April 2019 through 11 April 2019
ER -