Hybrid-Shield: Accurate and Efficient Cross-Layer Countermeasure for Run-Time Detection and Mitigation of Cache-Based Side-Channel Attacks

Cache-based Side-Channel Attacks (SCAs) exploit the emerging hardware vulnerabilities to steal secret information by observing cache access patterns of cryptographic applications. To address the challenges introduced by SCAs, existing solutions either rely on detecting them using the profiled hardware-related information of victim and attack programs, or mitigating the cache-based SCAs by focusing on cache partitioning techniques and/or randomization of cache mappings by modifying the underlying cache architecture of the processor. However, the former's detectors highly rely on the knowledge of attack programs that are not always available or could be obfuscated in real-world benign applications resulting in misidentifying attacks. On the other hand, the latter approach though effective, requires modification in the processor hardware which increases the complexity of architecture design and are not applicable to current as well as legacy architectures. To address the drawbacks, we propose Hybrid-Shield, an accurate and efficient cross-layer countermeasure for run-time detection and mitigation of cache-based side-channel attacks. For the detection stage, mi-croarchitectural information of victim under attack and under no attack conditions are collected for training machine learning classifiers. For the mitigation stage, Hybrid-Shield adapts hardware prefetchers and scales processor frequency to increase the noise level in observed cache access pattern attacks to induce secret information. The experimental results indicate that Hybrid-Shield can achieve 100% detection rate with 0% false alarm rate and detected attacks' error rate increases from less than 5% to above 35% with only 15% performance overhead.