What is a side-channel attack and what distinguishes it from direct attacks on cryptographic algorithms?

Question

Cybersecurity Fundamentals — Hard

What is a side-channel attack and what distinguishes it from direct attacks on cryptographic algorithms?

Accepted Answer

A side-channel attack exploits physical or indirect information leaked by a system during operation, such as timing or power consumption, rather than attacking the algorithm directly. This makes it different from direct attacks on cryptographic algorithms.