Researchers at Tel Aviv University and the Weizmann Institute of Science have successfully extracted 4096-bit RSA encryption keys using only the sound produced by the target computer.
The attack can extract full 4096-bit RSA decryption keys from laptop computers (of various models), within an hour, using the sound generated by the computer during the decryption of some chosen ciphertexts. We experimentally demonstrate that such attacks can be carried out, using either a plain mobile phone placed next to the computer, or a more sensitive microphone placed 4 meters away.
Beyond acoustics, we demonstrate that a similar low-bandwidth attack can be performed by measuring the electric potential of a computer chassis. A suitably-equipped attacker need merely touch the target computer with his bare hand, or get the required leakage information from the ground wires at the remote end of VGA, USB or Ethernet cables.
Such attacks aren’t really new: monitors, and in particular CRTs, have been susceptible to such attacks for nearly three decades, and it’s something that various security agencies around the world have taken seriously in that time.
Clearly, moving to newer systems hasn’t diluted the attack.