Physical layer secure transmission method and system based on dynamic change of channel encoding matrix

Abstract

The invention relates to a physical layer secure transmission method and system based on dynamic change of a channel encoding matrix, and belongs to the field of communication information security. The system comprises a joint encoder arranged on a physical layer of a transmitting end and a joint decoder arranged on a physical layer of a receiving end, and the transmitting end and the receiving end are communicated through a main channel. The method comprises steps as follows: a symmetric key obtained through key agreement is shared between the joint encoder at the transmitting end and the joint decoder at the receiving end on the basis of an existing key exchange protocol; a basic check matrix generated through optimized construction as well as a matrix extension factor is agreed publicly; joint encryption and error-control coding is performed on each transmitted plain text by the joint encoder, and corresponding code words in bit are obtained; the joint decoder decodes received code words into received plain texts at the receiving end. The method and the system can be used for realizing physical layer information transmission with high secrecy performance and high reliability.

Description

technical field [0001] The invention belongs to the field of communication information security, and relates to a physical layer security communication system based on dynamic change of channel coding matrix. Background technique [0002] With the rise of new technologies such as the mobile Internet and the Internet of Things, future wireless communication systems are faced with the dual challenges of efficient and reliable transmission of information and information security. Specifically, on the one hand, how to ensure the efficient and reliable transmission of information in a harsh electromagnetic environment is a major challenge; on the other hand, how to ensure the security of information transmission in an open electromagnetic environment is another Problems to be solved. [0003] The existing wireless communication system uses a transmission system that separates encryption and error correction, such as figure 1 As shown, the system includes an encryptor and a chan...

AI Technical Summary

Problems solved by technology

Through the method of information theory, it can be proved that assuming that the signal-to-noise ratio of the receiving end is greater than that of the eavesdropper, then the secure communication capacity is equal to the difference between the two channel capacities; method makes it impossible for an eavesdropper to obtain any information about the secret source

The disadvantages of this method are: first, the signal-to-noise ratio of the receiving end cannot be lower than that of any eavesdropper, and this assumption cannot be fully established in many scenarios; second, the sending end needs to understand the overall channel information of the communication system

The disadvantage of this scheme is that the existing designs all use a fixed secret channel coding matrix

However, since channel coding is a kind of linear coding, eavesdroppers can use known plaintext attacks to decipher the channel coding matrix by accumulating enough "plaintext-ciphertext pairs" even if they do not know the channel coding matrix

Therefore, the fixed secret channel coding matrix is ​​difficult to guarantee the security of transmission, and it is very easy to be cracked by eavesdroppers and cause information leakage.

[0007] From the above analysis, it can be seen that the first scheme solves the security of information transmission, but cannot guarantee the efficient and high reliability of information transmission; the second scheme can provide efficient and reliable transmission performance, but it is difficult to resist known plaintext Very low security due to attacks

Therefore, none of the above solutions can properly solve the contradiction between the reliability and security of physical layer information transmission, and neither can meet the needs of future broadband wireless communication

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