Highly Efficient Known-Plaintext Attacks Against Orthogonal Blinding Based Physical Layer Security

In this letter, we describe highly effective known-plaintext attacks against physical layer security schemes. We substantially reduce the amount of required known-plaintext symbols and lower the symbol error rate (SER) for the attacker. In particular, we analyze the security of orthogonal blinding schemes that disturb an eavesdropper´s signal reception using artificial noise transmission. We improve the attack efficacy using fast converging optimization algorithms and combining the measurements of neighboring subchannels in a multicarrier system. We implement the enhanced attack algorithms by solving unregularized and regularized least squares problems. By means of simulation, we show that the performance of the new attack algorithms supersedes the normalized least mean square approach discussed in the work of Schulz et al., e.g., by lowering the eavesdropper´s SER by 82% while using 95% less known plaintext.