TimeWarp: Rethinking timekeeping and performance monitoring mechanisms to mitigate side-channel attacks

Over the past two decades, several microarchitectural side channels have been exploited to create sophisticated security attacks. Solutions to this problem have mainly focused on fixing the source of leaks either by limiting the flow of information through the side channel by modifying hardware, or by refactoring vulnerable software to protect sensitive data from leaking. These solutions are reactive and not preventative: while the modifications may protect against a single attack, they do nothing to prevent future side channel attacks that exploit other microarchitectural side channels or exploit the same side channel in a novel way. In this paper we present a general mitigation strategy that focuses on the infrastructure used to measure side channel leaks rather than the source of leaks, and thus applies to all known and unknown microarchitectural side channel leaks. Our approach is to limit the fidelity of fine grain timekeeping and performance counters, making it difficult for an attacker to distinguish between different microarchitectural events, thus thwarting attacks. We demonstrate the strength of our proposed security modifications, and validate that our changes do not break existing software. Our proposed changes require minor - or in some cases, no - hardware modifications and do not result in any substantial performance degradation, yet offer the most comprehensive protection against microarchitectural side channels to date.

[1]  Jong-Deok Choi,et al.  An efficient cache-based access anomaly detection scheme , 1991, ASPLOS IV.

[2]  Jean-Pierre Seifert,et al.  On the power of simple branch prediction analysis , 2007, ASIACCS '07.

[3]  Simha Sethumadhavan,et al.  Rapid identification of architectural bottlenecks via precise event counting , 2011, 2011 38th Annual International Symposium on Computer Architecture (ISCA).

[4]  Hovav Shacham,et al.  Hey, you, get off of my cloud: exploring information leakage in third-party compute clouds , 2009, CCS.

[5]  Zhiqiang Ma,et al.  Demand-driven software race detection using hardware performance counters , 2011, 2011 38th Annual International Symposium on Computer Architecture (ISCA).

[6]  Hovav Shacham,et al.  Eliminating fine grained timers in Xen , 2011, CCSW '11.

[7]  Jean-Pierre Seifert,et al.  Advances on Access-Driven Cache Attacks on AES , 2006, Selected Areas in Cryptography.

[8]  Daniel J. Bernstein,et al.  Cache-timing attacks on AES , 2005 .

[9]  Ruby B. Lee,et al.  New cache designs for thwarting software cache-based side channel attacks , 2007, ISCA '07.

[10]  Dan Page,et al.  Partitioned Cache Architecture as a Side-Channel Defence Mechanism , 2005, IACR Cryptology ePrint Archive.

[11]  Onur Aciiçmez,et al.  Yet another MicroArchitectural Attack:: exploiting I-Cache , 2007, CSAW '07.

[12]  Stephan Krenn,et al.  Cache Games -- Bringing Access-Based Cache Attacks on AES to Practice , 2011, 2011 IEEE Symposium on Security and Privacy.

[13]  Simha Sethumadhavan,et al.  Side-channel vulnerability factor: A metric for measuring information leakage , 2012, 2012 39th Annual International Symposium on Computer Architecture (ISCA).

[14]  Colin Percival.  CACHE MISSING FOR FUN AND PROFIT , 2005 .

[15]  Josep Torrellas,et al.  ReEnact: using thread-level speculation mechanisms to debug data races in multithreaded codes , 2003, ISCA '03.

[16]  Josep Torrellas,et al.  SigRace: signature-based data race detection , 2009, ISCA '09.

[17]  Ruby B. Lee,et al.  A novel cache architecture with enhanced performance and security , 2008, 2008 41st IEEE/ACM International Symposium on Microarchitecture.

[18]  Darshana Jayasinghe,et al.  Remote Cache Timing Attack on Advanced Encryption Standard and countermeasures , 2010, 2010 Fifth International Conference on Information and Automation for Sustainability.

[19]  L MinSang,et al.  An efficient cache-based access anomaly detection scheme , 1991 .

[20]  Adi Shamir,et al.  Cache Attacks and Countermeasures: The Case of AES , 2006, CT-RSA.