Investigation of keyless cryptosystem proposed by dean and Goldsmith

We consider keyless cryptosystem proposed recently by Dean and Goldsmith. We show by simulation that this scheme is secure even so the eavesdropper uses suboptimal decoding (zero-forcing attack) with linear complexity but if the number of legitimate and eavesdropper antennas are equal to one another. But if eavesdropper has even small advantage in number of antennas, the proposed cryptosystem occurs insecure that we prove both theoretically and experimentally. We investigate a modified scheme with inverse precoder and show that it requires untractable values of the legitimate user transmitter power. Thus Dean-Goldsmith cryptosystem seems to be insecure with practical point of view.