Network Controlled PLS

A society without wireless devices is unthinkable. We’re reliant on wireless communication technologies to exchange personal and, sometimes, confidential data. The broadcasting nature of the wireless medium makes exposure to eavesdroppers a potential threat.

So far, this threat has mostly been mitigated by encrypting the wireless link and the information transmitted. Such a solution assumes that eavesdroppers lack the computational resources and knowledge of the network parameters to break the encryption. While this assumption still holds for many scenarios, eavesdroppers’ capabilities are rapidly improving, particularly with the availability of quantum computers on the horizon.

Physical-Layer Security (PLS), opens in a new window has been widely recognised as a complementary and, sometimes, alternative approach to encryption. PLS limits the amount of information that can be intercepted by assuring the signal contains so much noise at the electromagnetic level, that it’s impossible for eavesdroppers to decode any data, thus achieving perfect secrecy.

Several techniques have been proposed to implement PLS, falling into the categories of channel coding, channel control and power control. So far, these techniques remain limited to the information theory domain, without practical implementations.