Protection of ECC computations against side-channel attacks for lightweight implementations

Crypto-processors must be protected against various types of attacks to secure the access to the secret information. In the case of Elliptic Curve Cryptography (ECC), Simple Power Analysis (SPA) can be very efficient to recover the secret key if no protection is implemented. However, lightweight implementations necessary in Internet of Things (IoT) objects cannot afford the classical counter-measures. We propose and evaluate here a low-cost protection, based on the use of the general processor usually available in the system. We show the efficiency with respect to SPA, at no hardware and performance cost and limited power consumption increase. The implemented protection should also strengthen the system against more sophisticated attacks based on power or electromagnetic measurements.