Second Order Soft Tempest: from Internal Cascaded Electromagnetic Interactions to Long Haul Covert Channels

Many studies were devoted to the characterization, the analysis, the detection and the mitigation of TEMPEST and soft tempest attacks. Such attacks involve a direct interaction between the information processing in an electronic device and the related spurious electromagnetic emanations. Recently, second order soft tempest has been introduced, involving an indirect interaction through internal cascaded coupling effects. In this paper, a setup for investigating such threat is proposed and a proof of concept second order soft tempest attack is described.