Side-channel analysis is a class of security attacks that exploits information leaked inadvertently by a system's physical implementation during computation. This methodological approach investigates covert information channels such as power consumption fluctuations, execution timing variations, electromagnetic emissions, or acoustic signals to infer sensitive data, often cryptographic keys or secret states. Distinct from purely algorithmic analysis, side-channel analysis targets the physical manifestation of computation and is significant in evaluating and hardening the security of hardware and software implementations against practical attacks.