Timing Attack
What is Timing Attack?
Timing AttackA side-channel attack that recovers secret information by measuring how long an operation takes under different inputs.
Timing attacks exploit input-dependent execution time in cryptographic and authentication code. Classic targets are non-constant-time string comparisons (each early-mismatch byte short-circuits and reveals progress), modular exponentiation (square-and-multiply leaking key bits), AES table lookups, and database lookups whose duration depends on row existence. Even small differences — nanoseconds across a network, or microseconds locally — can be amplified by averaging many measurements. Defences require constant-time implementations (HMAC-style comparisons, branch-free conditional moves), library primitives like crypto_constant_time_eq, careful audit of cryptographic libraries, and rate-limiting or jitter at the boundary where attackers can measure.
● Examples
- 01
Kocher's 1996 attack against RSA blinding via timing analysis.
- 02
Lucky Thirteen (CVE-2013-0169) — TLS CBC padding timing attack.
● Frequently asked questions
What is Timing Attack?
A side-channel attack that recovers secret information by measuring how long an operation takes under different inputs. It belongs to the Vulnerabilities category of cybersecurity.
What does Timing Attack mean?
A side-channel attack that recovers secret information by measuring how long an operation takes under different inputs.
How do you defend against Timing Attack?
Defences for Timing Attack typically combine technical controls and operational practices, as detailed in the full definition above.
What are other names for Timing Attack?
Common alternative names include: Timing side-channel.