Get Your Hands Off My Laptop: Physical Side-Channel Key-Extraction Attacks on PCs

We demonstrate physical side-channel attacks on a popular software implementation of RSA and ElGamal, running on laptop computers. Our attacks use novel side channels, 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 exposed metal on the computer\u27s chassis with a plain wire, or even with a bare hand. The signal can also be measured at the remote end of Ethernet, VGA or USB cables. Through suitable cryptanalysis and signal processing, we have extracted 4096-bit RSA keys and 3072-bit ElGamal keys from laptops, via each of these channels, as well as via power analysis and electromagnetic probing. Despite the GHz-scale clock rate of the laptops and numerous noise sources, the full attacks require a few seconds of measurements using Medium Frequency signals (around 2 MHz), or one hour using Low Frequency signals (up to 40 kHz)

ECDH Key-Extraction via Low-Bandwidth Electromagnetic Attacks on PCs

We present the first physical side-channel attack on elliptic curve cryptography running on a PC. The attack targets the ECDH public-key encryption algorithm, as implemented in the latest version of GnuPG\u27s Libgcrypt. By measuring the target\u27s electromagnetic emanations, the attack extracts the secret decryption key within seconds, from a target located in an adjacent room across a wall. The attack utilizes a single carefully chosen ciphertext, and tailored time-frequency signal analysis techniques, to achieve full key extraction