With the rising importance of information security, the neces-sity of implementing better security measures in the physical layer as well as the upper layers is becoming increasing apparent. Given the development of more accurate and less expensive measurement devices, high-perfor-mance computers, and larger storage devices, the threat of advanced attacks at the physical level has expanded from the military and governmental spheres to commercial products. In this paper, we review the issue of infor-mation security degradation through electromagnetic (EM)-based compro-mising of security measures in the physical layer (i.e., EM information se-curity). Owing to the invisibility of EM radiation, such attacks can be seri-ous threats. We first introduce the mechanism of information leakage through EM radiation and interference and then present possible counter-measures. Finally, we explain the latest research and standardization trends related to EM information security.