Research Of RSA Encryption Algorithm And Improved Implementation

With the rapid development of IT technology, people depend on it increasingly, as a result, information security is getting more and more important. Meanwhile, products that ensure network information show a great prospect due to the importance of transmitting data by network safely ,and as an important means of information security, cryptography must be lifted.Cryptography is the core of the information security. Modern cryptograph is divided into the public key system and the private key system. The private key system is also called the single key system, in which the encryption process is the same as the decryption process. The public key system is also called the double key system, where the encryption process is different with the decryption process. Since the public key system can publish its public key and keep its private key secret, it has many new applications such as the digital signature and authentication, which is widely used in every field of the society.Among the various public key cryptosystem, RSA algorithm is the best choice in both theory and application, and it is open used in digital signature and identification system. Modular exponentiation and modular multiplication are the basic algorithms for implementing the public key algorithms such as RSA, etc. However the time-consuming modulo exponentiation computation, which has always been the bottle-neck of RSA, restricts iis wider application.The first chapter introduces the domestic and foreign progress of cryptograph; the RSA related tendency as well as the meaning of the research. The second chapter explains cryptograph. The third chapter describes and analyzes the RSA algorithm. The fourth chapter discusses the improvement of the RSA algorithm including the big number restore and operation, and the improvement algorithm of the "squaremultiply" algorithm. The fifth chapter reprents an improved algorithm and comparisons.