Qinhan Tan (Zhejiang University), Zhihua Zeng (Zhejiang University), Kai Bu (Zhejiang University), Kui Ren (Zhejiang University)

Cache conflicts due to deterministic memory-to-cache mapping have long been exploited to leak sensitive information such as secret keys. While randomized mapping is fully investigated for L1 caches, it still remains unresolved about how to secure a much larger last-level cache (LLC). Recent solutions periodically change the mapping strategy to disrupt the crafting of conflicted addresses, which is a critical attack procedure to exploit cache conflicts. Remapping, however, increases both miss rate and access latency. We present PhantomCache for securing an LLC with remapping-free randomized mapping. We propose a localized randomization technique to bound randomized mapping of a memory address within only a limited number of cache sets. The small randomization space offers fast set search over an LLC in a memory access. The intrinsic randomness still suffices to obfuscate conflicts and disrupt efficient exploitation of conflicted addresses. We evaluate PhantomCache against an attacker exploring the state-of-the-art attack with linear-complexity. To secure an 8-bank 16~MB 16-way LLC, PhantomCache confines randomization space of an address within 8 sets and brings only 0.5% performance degradation and 0.5% storage overhead per cache line, which are 3x and 9x more efficient than the state-of-the-art solutions. Moreover, PhantomCache is solely an architectural solution and requires no software change.

View More Papers

Unicorn: Runtime Provenance-Based Detector for Advanced Persistent Threats

Xueyuan Han (Harvard University), Thomas Pasquier (University of Bristol), Adam Bates (University of Illinois at Urbana-Champaign), James Mickens (Harvard University), Margo Seltzer (University of British Columbia)

Read More

CV-Inspector: Towards Automating Detection of Adblock Circumvention

Hieu Le (University of California, Irvine), Athina Markopoulou (University of California, Irvine), Zubair Shafiq (University of California, Davis)

Read More

On Building the Data-Oblivious Virtual Environment

Tushar Jois (Johns Hopkins University), Hyun Bin Lee, Christopher Fletcher, Carl A. Gunter (University of Illinois at Urbana-Champaign)

Read More

Safer Illinois and RokWall: Privacy Preserving University Health Apps...

Vikram Sharma Mailthody, James Wei, Nicholas Chen, Mohammad Behnia, Ruihao Yao, Qihao Wang, Vedant Agarwal, Churan He, Lijian Wang, Leihao Chen, Amit Agarwal, Edward Richter, Wen-mei Hwu, and Christopher Fletcher (University of Illinois at Urbana-Champaign); Jinjun Xiong (IBM); Andrew Miller and Sanjay Patel (University of Illinois at Urbana-Champaign)

Read More