Abstract:In order to realize the Linux server and client system file encryption transmission, fully guarantee the transmission process of data confidentiality, I studied the RSA encryption algorithm and the characteristics of thread pool. To use the Openssl of Linux to realize the encryption process neatlyS and to deal with one server to multiple clients process encryption communication by using thread pool. The experimental results show that the successful use of ARM platform as the client, to connect the server, and complete the RSA encryption process and file transfer process. The design of asymmetric encryption algorithm can be applied to many of the embedded operating platform with network transmission function.