Research On RSA Improved Algorithm Based On

Information security attracted more and more attention, which makes the information security technology to achieve rapid development. According to the needs of all kinds of information technologies and applications, many encryption algorithms have been proposed. While the appearance of asymmetric encryption system marks the gradual improvement of cryptosystem.RSA is considered to be a typical algorithm and standard template in the study of public key cryptosystems. Modular exponentiation is the most common fundamental and time consuming operation in RSA cryptosystems. In order to guarantee the security of encrypted data, the basic principle is to increase the number of bits of RSA’s key. But the key digit growth means slower encryption and decryption, therefore a better way should be found to improve the RSA algorithm, and makes it faster. Interface can enable multiple nodes to work together to complete the calculation, thereby reducing computation time by using the MPI message passing parallel interface.In this thesis, we firstly study the theory basic of RSA algorithm. First of all, decomposing plaintext will help to get the factors. Based on characteristics that a large integer which can be divided by co-prime two integers will be divided by the product of the two integers, we designed a fast method of big integer factorization. Moreover, the factors which were decomposed by the large integer will be grouped. Because of the big integer grouping parallel computing time depends on the longest running process, small decomposed integers should be sorted for realizing the average packets. At last, the average grouped packets will be parallel computed. The purpose is to make large integer exponentiation converted to some small integer exponentiation. The computing time was saved and the efficiency of the algorithm is improved, by the way of sorting on the factors which are obtained by decomposing, moreover grouping the sorted factors by average. Consequently many balanced subtasks are produced, and MPI parallel computing will be used to save operation time. The experimental results show that the RSA algorithm based on MPI parallel can effectively improve the computational speed of the algorithm.