Glitch Attack.

A fault-injection technique that briefly perturbs voltage or clock signals to make a chip skip instructions or leak cryptographic secrets. It belongs to the Cryptography category of cybersecurity.

A fault-injection technique that briefly perturbs voltage or clock signals to make a chip skip instructions or leak cryptographic secrets.

A glitch attack is an active fault-injection technique in which the attacker deliberately disturbs the supply voltage or clock of a microcontroller or secure element for a few nanoseconds to induce a controlled fault. Typical effects include skipping a conditional branch, corrupting a comparison, or producing a faulty signature that, combined with a correct one, yields the private key (differential fault analysis on RSA-CRT or ECDSA). Practitioners use cheap tools such as ChipWhisperer or laser pulses for more precise localized faults. Countermeasures include voltage and clock monitors, redundant computation, double-check of cryptographic results, fault-detecting code paths, randomized delays, and shielded packages compliant with FIPS 140-3 Level 3 or 4.

Defences for Glitch Attack typically combine technical controls and operational practices, as detailed in the full definition above.

Common alternative names include: Voltage glitching, Clock glitching, Fault injection.