Review on Physical- Layer Security Techniques of Wireless Communications
Liu Zai-shuan · Communications technology · 2014
Due to the openness and broadcast nature of wireless mediums,wireless communication is always vulnerable to potential security threats such as eavesdropping,since unauthorized receiving is facilitated through wireless channels. Traditional system security is always implemented in the higher layers of the communication protocol stack,relying on authentication and cryptography,but independent of the physical layer. However,in recent years,wireless communications security gradually becomes a hot research topic from a physical layer perspective. As an important complement to the traditional security mechanism,the physical layer security technique can protect the information over wireless transmission and prevent the unauthorized from illegally receiving and extracting confidential messages. This paper makes a review on the physical layer security techniques,and introduces several representative paradigms,including principle of information theoretic security,transmit- signal security techniques,spread spectrum and frequency- hopping encryption techniques,cryptosystem based on channel coding,modulation encryption techniques and so on. Finally the prospects of cross- layer security design and moving target defense are also described.