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Speculative execution attacks like Spectre and Meltdown exploit hardware performance optimization features to illegally access a secret and then leak the secret to an unauthorized recipient. Many variants of speculative execution attacks (also called transient execution attacks) have been proposed in the last few years, and new ones are constantly being discovered. While software mitigations for some attacks have been proposed, they often cause very significant performance degradation. Hardware solutions are also being proposed actively by the research community, especially as these are attacks on hardware microarchitecture. In this talk, we identify the critical steps in a speculative attack, and the root cause of successful attacks. We define the concept of "security dependencies", which should be implemented to prevent data leaks and other security breaches. We propose a taxonomy of defense strategies and show how proposed hardware defenses fall under each defense strategy. We discuss security-performance tradeoffs, which can decrease the performance overhead while still preventing security breaches. We suggest design principles for future security-aware microarchitecture.
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Invulnerability invariants for software controlled speculation
Abstract Spectre class of transient execution security attacks on modern microprocessors rely on speculative execution. Software Controlled Speculation (SCS) was proposed as a microarchitecture‐level defense in the original Spectre paper and has also been adopted by ARM. The idea with SCS is to allow a mode in the microarchitecture, where instructions that read from memory are not allowed to execute speculatively. Errors or malicious fault‐injections in the implementation of SCS can still render the microarchitecture vulnerable to Spectre attacks. A formal verification method is proposed that can check the correctness of the implementation of SCS and detect any faults. The method has been demonstrated to be very efficient on two sets of benchmarks and provides accurate detection of implementation faults in SCS.
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- Award ID(s):
- 2117190
- PAR ID:
- 10570814
- Publisher / Repository:
- DOI PREFIX: 10.1049
- Date Published:
- Journal Name:
- Electronics Letters
- Volume:
- 60
- Issue:
- 23
- ISSN:
- 0013-5194
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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