Abstract

Can secret information be extracted from personal computers by measuring their physical properties from the outside? What would it take to extract whole keys from such fast and complex devices? We present myriads way to do so, by analyzing signals acquired through microphones, antennas, paper clips, or even the touch of a human hand. The talk will discuss the attacks’ principles.

For example, many computers emit a high-pitched noise during operation, due to vibration of electronic components. These acoustic emanations, we show, can be exploited to extract 4096-bit RSA secret keys from the popular GnuPG software, within an hour—just by pointing a microphone at the computer while it is decrypting carefully-crafted ciphertexts.

Additional attacks are based on the observation that the “ground” electric potential, in many computers, fluctuates in a computation-dependent way. An attacker can measure this signal by touching the computer’s chassis, or the shield on the remote end of Ethernet, VGA or USB cables. Secret keys can then be extracted, sometimes within seconds.

Joint works with Daniel Genkin, Itamar Pipman and Adi Shamir. For further information on the acoustic key extraction, see http://www.cs.tau.ac.il/~tromer/acoustic .