Clock Glitching

Clock glitching is a fault injection technique that involves momentarily speeding up or disrupting the clock signal of a processor to cause it to skip or incorrectly execute instructions. By forcing the processor to move to the next state before it has completed a critical calculation, an attacker can bypass security checks, such as those used for signature verification in blockchain transactions.

This attack is particularly effective because it requires very little specialized equipment and can be performed on many common microcontrollers. In the context of crypto-wallets, a well-timed clock glitch can trick the device into authorizing a transaction without the correct PIN.

To defend against this, developers must implement robust clock monitoring circuits that detect frequency deviations and force a reset. It is a classic example of how timing and hardware stability are inextricably linked to financial security.