PC lock software design based on removable storage device and dynamic password

The traditional mechanical key of PC has only the device authentication or the static password authentication function, which is easily copied, decrypted and forgotten. To solve these problems, the PC lock software based on removable device is developed. The software design principles and the MD5 (Message-Digest Algorithm 5) encryption algorithm are introduced, and the modules of the software are described in detail. Some important code was also provided. The advantages of the software are as follows. First, the use of removable storage device lock makes unlock unique. It breaks through the traditional password that anyone who knows the password can login the computer. Second, the dual protection of equipment certification and dynamic password card nearly eliminates the possibility of brute force cracking the code. It protects the personal computer security more effectively. Finally, the one-way hash encryption algorithm of MD5 ensures the uniqueness of the key, the technology of double process protection prevents an illegal program to forcibly damage this software. The experiment indicated the software is low cost, high stability, easy to use. It is suitable for a variety of computer equipments.