Physical Layer Key Extraction Method Based on Channel Characteristics

Abstract

The present invention provides a method for extracting physical layer keys based on channel characteristics. Both legitimate communication parties obtain the channel characteristic sequence through channel estimation, and then introduce an improved level-crossing algorithm to filter and accumulate the channel characteristic sequence to update the channel characteristic sequence. . Afterwards, the KL transformation is used to remove the correlation between the sampled values ​​of the updated channel feature sequence. Finally, the correlation-removed channel signature sequence is quantized into a key bit string by using a multi-bit adaptive quantization (MAQ) scheme. Experimental results show that the present invention has a higher key generation rate than the level-crossing key generation scheme, and has a better key inconsistency rate than the HRUBE scheme, and the key bit string generated by the scheme meets the randomness requirement, No key enhancement processing is required.

Description

technical field [0001] The invention belongs to the field of physical layer security in wireless communication technology, and relates to an improved key generation method based on wireless channel reciprocity, in particular to a physical layer key extraction method based on channel characteristics. Background technique [0002] In recent years, with the rapid development of wireless mobile communications, the number of users and the scope of applications of wireless networks have been increasing, and the security of wireless communications has also attracted more and more attention. Most of the traditional security methods rely on authentication and encryption technology, implemented through the upper layer protocol of the network, and are relatively independent from the physical layer. In view of the openness and broadcast nature of wireless communication, the computing security provided by traditional algorithms has been widely questioned by the industry. Therefore, rese...

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Problems solved by technology

The inconsistency rate of the key bit string generated by this scheme is low, and the implementation is simple, but the key generation rate is low

[0005] In order to increase the key generation rate, N.Patwari et al. proposed the HRUBE scheme in 2009, [N.Patwari, J.Croft, and S.Jana, "High-rate uncorrelated bit extraction for shared secret key generation from channel measurements, ”IEEE Trans.MobileComput.,vol.9,pp.17–30,Jan.2009.] This scheme proposes a multi-bit adaptive quantization scheme (MAQ), which can extract multiple bits from a channel characteristic sampling value The key greatly increases the key generation rate, but its disadvantage is that the key inconsistency rate generated by both communication parties is high, and the generated key string needs to be enhanced to remove redundant information

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