The diversity of Instruction Set Architectures (ISAs), each with unique limitations and optimization strategies, presents both opportunities and challenges in processor design. Modern processor vendors leverage these ISAs to enhance security, reliability, and performance. Recent security vulnerabilities, notably Spectre and Meltdown, have underscored the importance of robust hardware security measures. The recent discovery of attacks such as Specter and Meltdown had a high impact on the vendors regarding hardware security. Processor micro-architectures are susceptible to side-channel attacks, which exploit information leakage to identify vulnerabilities. Techniques such as speculative execution and branch prediction, commonly employed by processors from AMD, Intel, and ARM, while beneficial for performance optimization, inadvertently create avenues for such attacks. Additionally, the practice of out-of-order execution, designed to maximize efficiency, can be manipulated to form side channels, further compromising security. Additionally, shared memory resources, particularly cache memory, are another vector for attack. By analyzing access patterns to shared caches, attackers can construct cache-based side channels, facilitating sophisticated attacks like FLUSH+Reload and Prime+Probe.
In response to these threats, this work proposes a comprehensive mechanism for securing processor micro-architectures against side-channel attacks. Our methodology comprises five stages:
(1) identifying and developing attack vectors, (2) compiling these attacks across various architectures, (3) scripting simulations using the Gem5 tool, (4) running these simulations, and (5) analyzing the resultant attack traces to understand and mitigate vulnerabilities. These stages are detailed in the next paragraphs.