We show that elliptic-curve cryptography implementations on mobile devices are vulnerable to electromagnetic and power side-channel attacks. We demonstrate full extraction of ECDSA secret signing keys from OpenSSL and CoreBitcoin running on iOS devices, and partial key leakage from OpenSSL running on Android and from iOS's Common-Crypto. These non-intrusive attacks use a simple magnetic probe placed in proximity to the device, or a power probe on the phone's USB cable. They use a bandwidth of merely a few hundred kHz, and can be performed cheaply using an audio card and an improvised magnetic probe. * The authors thank Noam Nissan for programming and lab support during the course of this research.

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's 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).

We present new side-channel attacks on RSA and ElGamal implementations that use sliding-window or fixed-window (m-ary) modular exponentiation. The attacks extract decryption keys using a very low measurement bandwidth (a frequency band of less than 100 kHz around a carrier under 2 MHz) even when attacking multi-GHz CPUs.We demonstrate the attacks' feasibility by extracting keys from GnuPG (unmodified ElGamal and non-blinded RSA), within seconds, using a nonintrusive measurement of electromagnetic emanations from laptop computers. The measurement equipment is cheap and compact, uses readily-available components (a Software Defined Radio USB dongle or a consumer-grade radio receiver), and can operate untethered while concealed, e.g., inside pita bread.The attacks use a few non-adaptive chosen ciphertexts, crafted so that whenever the decryption routine encounters particular bit patterns in the secret key, intermediate values occur with a special structure that causes observable fluctuations in the electromagnetic field. Through suitable signal processing and cryptanalysis, the bit patterns and eventually the whole secret key are recovered.

No abstract

Computers broadcast their secrets via inadvertent physical emanations that are easily measured and exploited.