Do Electromagnetic Side-Channel Attacks Threaten Electronic Polling Stations? Scenarios and Recommendations

• Lucas Brito UTFPR
• Leonardo Teodoro UTFPR
• Pedro Tomaz UTFPR
• Alyson Isaluski UTFPR
• Leandro Hyeda UTFPR
• Antonio Oliveira-Jr UFG / Fraunhofer Portugal AICOS
• Saulo Queiroz UTFPR

DOI: https://doi.org/10.5753/sbseg.2026.29396

Abstract

This paper investigates the threat of violating the secrecy of the Brazilian electronic voting machine through electromagnetic side-channel attacks, also known as TEMPEST attacks. In such attacks, screen information can be remotely reconstructed by intercepting electromagnetic emanations associated with the graphical signal of the target device. This work is motivated by the decision of electoral court in Brazil, in revoking a councilman’s mandate due to the ballot secrecy violation based on electronic equipment. Based on publicly available information of the electoral process, attack scenarios against electronic polling stations are proposed. Experiments using software-defined radio demonstrate that the effectiveness of TEMPEST attacks is strongly conditioned by the absence of monitoring due to public unawareness of the threat Finally, awareness guidelines are proposed for voters, poll workers, and party representatives in order to mitigate attack risks in the context of an electronic polling station.

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