Timing Attack
Timing attacks, introduced by Kocher, exploit tiny key-dependent variations in execution time to recover keys bit by bit.
Purpose
They assess whether a cryptographic implementation runs in data-independent time; RSA (CRT branching) and AES (table lookups) have been threatened by timing attacks.
Mechanism
Execution times for different inputs under the same key are measured, and the correlation between timing differences and key-bit hypotheses is analyzed — the hypothesis with the highest correlation gives the correct key bit. Defense requires constant-time implementations.
Use cases
- RSA implementation security
- AES T-table timing
- Diffie-Hellman security