Design of a Single-Shot Signal Amplifier based on Prefetching Instruction

Microarchitectural attacks increasingly exploit performance-enhancing components such as branch predictors, caches, and hardware prefetchers. This paper introduces a single-shot signal amplification method based on PRFM prefetch instructions, enabling active cache state manipulation to enhance side-channel attacks. Our method significantly improves signal-to-noise ratio, reduces reliance on high-precision timers, and effectively amplifies microarchitectural leakage in constrained environments. Experimental results on Raspberry Pi 4B demonstrate a $6.1 \times$ amplification factor and 95% cache state detection accuracy, even under low-precision timer conditions. Compared to conventional methods, our approach reduces the number of required attack samples while maintaining high reliability. This research provides new insights into efficient cache-side channel exploitation and defense strategies.