Improvement Of Encryption Algorithm And Broadcast Authentication Algorithm Based On Wireless Sensor Network SPINS Security System

For the wireless sensor network in most commercial applications, such as environmental monitoring, forest fire prevention, smart home, security is not very important. While in other special areas, such as sensor network in the areas of military, the financial areas, the security of wireless business district network, data sampling process, data transmission process and managing, the physical distribution of nodes or routing mode cannot be known by the enemy personnel or malicious nodes. In these applications, security is particularly important.The characteristics of wireless sensor network and the traditional network security determine that they are very different in the research method and calculation method. The data storage, computing, processing ability of network terminal unit of wireless sensor network node is more poor than the ones in the Internet. Therefore, there is a strength tradeoff between the calculate algorithm and the security algorithm. And the key is to strengthen the security shell through a simpler algorithm. In this paper the two part contents based on SPINS security protocol is:SNEP(Security Network Encryption Protocol) and μTESLA(micro Timed Efficient Streaming Loss-Tolerant Authentication Protocol). Both the security encryption algorithm and the broadcast authentication protocol are improved here.Firstly, the advantages and disadvantages of the working principle of the RC5encryption algorithm, the encryption and decryption process and the application in the wireless sensor network are analyzed according to the poor security, poor network expansion and the difficulties in the digital signature. Therefore, RSA algorithm is introduced, by the hybrid encryption mechanism to encrypt the symmetric key algorithm through the RSA algorithm, RC5algorithm symmetric key encrypt the text.Secondly, with regard to the broadcast authentication protocol, the shortcomings of μTESLA protocol is analyzed, such as over reliance on the base station, periodic report the key, authentication delay, the characteristic that is vulnerable to DoS attacks and other weaknesses. And afterward, an improved broadcast authentication algorithm is proposed from the three aspects to improve the algorithm---cluster based routing improvement, regeneration of hash key chain, release time of the key.Finally, by using NS2simulation software, hybrid encryption algorithm is verified to be more superior than the original one, respectively from the size of cipher text, the efficiency of encryption and decryption, packet loss rate and other indicators. And the improved broadcast authentication algorithm is also superior in its performance, such as the packet loss rate, throughput indicators, delay and energy and other indicators.