The Public Trunking Communication System Voice Encryption Technology Research

The trunking communication plays very important part in the police detection, and the information security of communication needs high level protection. The paper is focused on voice encryption sub-system development for the police trunking communication of Wuhan, Hubei province. Based on the TETRA features and the actual trunking equipment specification, with the analysis and comparison for the encryprtion algorithm, the author designs the project of the encryption sub-system. In a point to point encryption of the TETRA system, the trunking system does not participate in the key generation and management, and only provides the clear channel for transportation. The point to point encryption of TETRA occurs in the user interface, and the trunking endpoints have electronic and physical interfaces for encryption to intergrate the encryption system to the endpoint. A point to point encryption solution is provided in this paper, which shows the procedure of a secure communication from tranciever to the receiver, and this solution is suitable for the case of special security needs. The algorithm selection shows RSA suits public key encryption and AES is good for voice encryption. The AES software development gives the algorithm engineering process, and the optimized software only ocuppies lower CPU resource, which means it is very easy to be intergrated into the embedded system. The hardware platform with ARM7 kernal design meets the demands of the endpoint equipment and the AES software, the main software is given in this paper. The software is migratable, so the sub-system can be used not only in Wuhan trunking communication system but also in the places of the other same envoriment.