Seonglae ChoA side-channel attack is any attack based on information gained from the implementation of a computer system, rather than weaknesses in the implemented algorithm itself.
Timing information, power consumption, electromagnetic leaks, and sound are examples of extra information which could be exploited to facilitate side-channel attacks from inference.
- Data cache footprint
- Instruction cache footprint
CPU caches are shared between the victim and the attacker when Multi-tenancy systems are prevalent. (Deduplication by flushing)
Cache footprint for Cryptographic Operation
Revealing cryptographic keys in cryptographic operation by utilizing possible footprints. Data access footprint (e.g., S-box table in AES) or instruction access footprint (branches that depend on secret key) are them.
Cache Side-Channel Attacks
Prevention (Side channel mitigation)
- Disable sharing like disable page deduplication, disable sharing cache via cache partitioning
- Prefetching implementation for OpenSSL Version 1.0.0a pre-fetches the S-Box table at the start of each round
- Put more data in a single cache line such as OpenSSL Version 1.0.0a uses a 256-byte S-box
- Lower timer resolution for managed languages (This is the reason why most of high level languages do not provide accurate timer)
- Secret independent execution flow/memory accesses
- Prevent
clflushin user-mode - PRIME+PROBE is still available tho