One major security problem at the physical layer of a wireless system is its vulnerability to pilot contamination attacks. A potential method for the detection of such active attacks involves training with two N-PSK pilots which however suffers from operational problems. In this paper we propose and evaluate the Shifted 2-N-PSK technique as an improvement on the original method. The Shifted 2-N-PSK method operates with two pilots from different constellations, each of which is shifted from the original N-PSK constellation. The performance of three variations of Shifted 2-N-PSK is presented and the most effective implementation of the technique is revealed to be when neither the shift values nor the difference between them equal an N-PSK angle. Experimental results are also provided, in order to confirm the theoretical estimates. In addition, a detailed analysis of the shift values and the number of their optimal combinations are presented for different accuracies.