Research On Information Security Of Perception Layer In The Internet Of Things Based On AES Algorithm

As the most critical underlying architecture of the Internet of Things,the perception layer has become more and more important.As one of the most effective security measures,encryption algorithms have also received widespread attention.Among them,AES(Advanced Encryption Standard)algorithm has the characteristics of high security,fast encryption and decryption speed,etc.Therefore,this thesis addresses the problem of low encryption and decryption efficiency and weak security between existing nodes in the Internet of Things sensing layer,in the advanced encryption standard AES.Based on the research,through analysis and comparison of LAES(Lightweight AES)algorithm,the data encryption method AES-I(Advanced Encryption Standard in IoT)in the Internet of Things environment is constructed.The main contents of this thesis are as follows:(1)For the problem that the sensing node system has limited resources and low encryption and decryption efficiency,the complexity of the algorithm is reduced by combining the original algorithm with the optimization and table lookup optimization,so as to adapt to the environmental characteristics of the Internet of Things.Firstly,under the premise of not affecting the internal operation of the round function,the encryption and decryption process of the algorithm is separately optimized.In the encryption process,the row shift and the column hybrid transform are combined;in the decryption process,the first exchange is performed separately.The order of retrograde shift and inverse byte substitution,round key addition and inverse column mixing,and then merged,this operation simplifies the encryption and decryption process of the algorithm and improves the efficiency of the algorithm operation.Secondly,the multiplex table method is used to optimize the AES algorithm by using the table lookup operation,which simplifies the round transformation of the AES algorithm,further reduces the time consumed by the algorithm,and greatly improves the computational efficiency.(2)For the problem that the security of the algorithm application may be weakened in the perception layer environment,when designing the key expansion algorithm of AES-I,the generation method of the subkey is changed.It is improved by generating a random number combined with a unidirectional key,complicating the key generation,and using the shift operation to reduce the correlation between the two sets of round keys.The key generation algorithm of AES-I effectively overcomes the inherent defects of the original extended key algorithm which is easy to derive all keys from two adjacent round keys,and enhances the security of the algorithm.Finally,this thesis uses the C++ language to design and implement the AES-I algorithm.By repeating the encryption of different sizes of data blocks in the same environment,the time of encryption and decryption of AES,LAES and AES-I algorithm is tested respectively,and then simulated by MATLAB software.The results prove that the AES-I algorithm has higher execution efficiency.At the same time,it can be seen from the analysis that AES-I has good security,so it is suitable for providing security protection for the data in the IoT environment.