Intentional electromagnetic interference is an effective mean to jeopardize the security of integrated circuits. In this paper, we propose a new approach to evaluate the efficiency of magnetic probes used to radiate a disturbance: measuring its impact within the target of the attack, more precisely on the propagation delay of a combinational path. The characterization of five probes carried out using three different integrated circuits is reported. In all cases, bespoke, handmade probes outperform commercial ones. Experimental results also show that the electromagnetic coupling between the probes and the integrated circuits is mainly due to global, bonding wires. Index Terms-Side-channel attacks, immunity testing, probes, field programmable gate array.

Electromagnetic fault injection is a growing topic when it is applied to jeopardize the security of integrated circuit. Indeed, if the main part of the process will focus on the hardware efficiency of the near-field probes, tweaking properties of the electromagnetic disturbance can also lead to the success of the attack. In this paper, we are presenting characterization results of intentional electromagnetic interference by measuring its impact within the target, and more precisely on the propagation delay of a combinational logic path. The evaluation of the impact shows that the electromagnetic coupling between the probe and the integrated circuit strongly depends on the characterized properties. Index Terms-Side-channel attacks, immunity testing, probes, field programmable gate array.