Michael Schwarz (Graz University of Technology), Moritz Lipp (Graz University of Technology), Claudio Canella (Graz University of Technology), Robert Schilling (Graz University of Technology and Know-Center GmbH), Florian Kargl (Graz University of Technology), Daniel Gruss (Graz University of Technology)

Out-of-order execution and speculative execution are among the biggest contributors to performance and efficiency of modern processors. However, they are inconsiderate, leaking secret data during the transient execution of instructions. Many solutions and hardware fixes have been proposed for mitigating transient-execution attacks. However, they either do not eliminate the leakage entirely or introduce unacceptable performance penalties.

In this paper, we propose ConTExT, a Considerate Transient Execution Technique. ConTExT is a minimal and fully backwards compatible architecture change. The basic idea of ConTExT is that secrets can enter registers, but not transiently leave them. ConTExT transforms Spectre from a problem that cannot be solved purely in software, to a problem that is not easy to solve, but solvable in software. For this, ConTExT requires minimal modifications of applications, compilers, operating systems, and the hardware. ConTExT offers full protection for secrets in memory and secrets in registers. With ConTExT-light, we propose a software-only solution of ConTExT for existing commodity CPUs protecting secrets in memory. We evaluate the security and performance of ConTExT. Even when over-approximating, we observe no performance overhead for unprotected code and data, and an overhead of 71.14% for security-critical applications, which is below the overhead of currently recommended state-of-the-art mitigation strategies.

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ProtectIOn: Root-of-Trust for IO in Compromised Platforms

Aritra Dhar (ETH Zurich), Enis Ulqinaku (ETH Zurich), Kari Kostiainen (ETH Zurich), Srdjan Capkun (ETH Zurich)

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Finding Safety in Numbers with Secure Allegation Escrows

Venkat Arun (Massachusetts Institute of Technology), Aniket Kate (Purdue University), Deepak Garg (Max Planck Institute for Software Systems), Peter Druschel (Max Planck Institute for Software Systems), Bobby Bhattacharjee (University of Maryland)

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Custos: Practical Tamper-Evident Auditing of Operating Systems Using Trusted...

Riccardo Paccagnella (University of Illinois at Urbana–Champaign), Pubali Datta (University of Illinois at Urbana–Champaign), Wajih Ul Hassan (University of Illinois at Urbana–Champaign), Adam Bates (University of Illinois at Urbana–Champaign), Christopher W. Fletcher (University of Illinois at Urbana–Champaign), Andrew Miller (University of Illinois at Urbana–Champaign), Dave Tian (Purdue University)

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CDN Judo: Breaking the CDN DoS Protection with Itself

Run Guo (Tsinghua University), Weizhong Li (Tsinghua University), Baojun Liu (Tsinghua University), Shuang Hao (University of Texas at Dallas), Jia Zhang (Tsinghua University), Haixin Duan (Tsinghua University), Kaiwen Sheng (Tsinghua University), Jianjun Chen (ICSI), Ying Liu (Tsinghua University)

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