Comparative Analysis of Quantization Schemes for Physical Layer Key generation

Wireless networks get subjected to the different attacks because of it's open nature. Eavesdropping attack, which occurs at the Physical layer of the OSI model, has a great impact on wireless network security. Conventional security in wireless networks depends on the cryptographic techniques. But in wireless sensor networks where a key management infrastructure may not be present and the power resources are also limited, generating a cryptographic key between two mobile entities becomes difficult. Hence Physical layer Security (PLS) has become a novel research solution. In PLS based key generation, a symmetric secret key is obtained at both the ends of the legitimate users using the properties of wireless channel. The key generation process includes four major blocks namely channel measurement, quantization of input samples, error detection and correction and privacy amplification. The output of quantizer has a great effect on the bit mismatch rate (BMR) between the two legitimate users. It also has an impact on key generation rate (KGR). Hence selecting a proper quantizer becomes very essential. In this paper different Quantization schemes are analyzed to achieve effective PLS between the two legitimate users.