Clock Glitching Fault Injection

Clock glitching is a fault injection technique that intentionally manipulates the clock signal supplied to a device. By introducing carefully controlled timing anomalies, security engineers can cause instructions, cryptographic operations, or security checks to execute outside their intended timing conditions, potentially exposing vulnerabilities.

Clock glitching works by temporarily altering the timing characteristics of the clock signal driving a device. This may involve speeding up, slowing down, shortening, or otherwise modifying clock cycles during a specific operation.

If the fault occurs at the right moment, the device may misinterpret data, skip instructions, or execute security-critical operations incorrectly.

The clock acts as the timing reference for most digital circuits. It controls when instructions are executed, data is moved, memory is accessed, and cryptographic operations occur.

Because so many device functions depend on accurate timing, even small disturbances can create unexpected behavior that may reveal security weaknesses.

Clock glitching is commonly used to investigate:

• Secure boot bypasses
• Authentication bypasses
• Cryptographic vulnerabilities
• Timing-related security weaknesses
• Fault injection resistance
• Security countermeasure effectiveness

The technique helps identify whether security-critical operations can be disrupted through carefully timed faults.

Successful clock glitch attacks often depend on modifying the clock signal during a very specific operation, such as a security check or cryptographic calculation.

Accurate timing allows engineers to consistently target the same operation, improving attack repeatability and making it easier to reproduce and analyze successful fault conditions.

Yes. Clock glitching can be integrated with Inspector software and automated test workflows to perform parameter sweeps, trigger-based attacks, campaign execution, and result analysis. Automation helps identify successful attack conditions more efficiently.

Yes. Security engineers often combine clock glitching with voltage glitching, electromagnetic fault injection (EMFI), or laser fault injection to evaluate a device from multiple attack angles and better understand its overall resilience.

Yes. The DS1150A integrates with Inspector software, enabling automated attack campaigns, parameter exploration, trigger management, and result analysis. This helps security teams perform repeatable and scalable clock fault injection evaluations.