Hardware Security
What is the main reason cache-based side-channel attacks work?
- ACaches can be shared between processes, so which data another process used can be observed as differences in one's own access speed (hit or miss)
- BAnyone can directly read the contents of a cache
- CCaches save data to disk unencrypted
Show answer and explanation
Answer: A. Caches can be shared between processes, so which data another process used can be observed as differences in one's own access speed (hit or miss)
Cached data is read fast and uncached data slowly. If an attacker fills part of a shared cache with its own data and later times reads of it, it can tell whether another process used those locations and evicted its data. If cryptographic code reads different table locations depending on the key, key information leaks this way.
- A. Correct. Access time becomes a trace.
- B. The contents are not read directly; they are inferred from timing.
- C. Caches do not save to disk.