Journal of Theoretical and Applied Information Technology
For professional software products, software developers must develop software registration authorization module in order to prevent illegal software theft and transfer. Currently, the main software encryption methods are symmetric cryptosystem and asymmetric cryptosystem. Symmetric cryptosystem mainly covers AES (Advanced Encryption Standard), DES (Data Encryption Standard), IDEA (International Data Encryption Algorithm) and so on. Symmetric cryptosystem security depends on the confidentiality of secret key, so security is not enough. The main stream of asymmetric cryptosystem which is also called public key cryptosystem is divided into three parts: based on the difficulty of the big integer factorization, the difficulty of the discrete logarithm calculation and elliptic curve public key cryptography.