Electromagnetic Analysis
Electromagnetic analysis is a side-channel attack that involves measuring the electromagnetic emissions of a device while it performs cryptographic operations. Every electronic component emits electromagnetic radiation as current flows through it, and these emissions can be captured by an antenna and analyzed.
Similar to power analysis, the captured signal can be correlated with the data being processed, potentially revealing private keys or other sensitive information. This attack can be performed from a distance, making it more covert than power analysis, which usually requires physical contact with the device's power supply.
Defense against electromagnetic analysis includes shielding the device with metal enclosures and implementing internal hardware countermeasures that randomize or mask the emissions. It is a major concern for secure element chips and other hardware security modules that operate in environments where physical access cannot be fully controlled.
This attack illustrates the complexity of protecting hardware, as even invisible emissions can be used to compromise the most secure systems.