Side-Channel Attack
Side-channel attacks recover keys from physical leakage of a cryptographic implementation (timing, power, EM, cache) rather than mathematical weaknesses.
Purpose
They assess cipher security on real hardware, where even a mathematically secure implementation can be broken through side channels.
Mechanism
The attacker measures physical signals during cryptographic execution (running time, power traces, EM radiation, cache-access patterns) and amplifies tiny key-dependent differences into observable quantities via statistical analysis (e.g., DPA).
Use cases
- Smart-card security assessment
- Embedded cryptographic implementations
- TLS Heartbleed