Existing file protection approaches and the applications are suitable for the users who own one single device but not the users with multiple devices. A novel mechanism is proposed that provides an efficient and fast cryptographic-based protection approach for files in an appointed directory called safe directory. The highlights are its ability to protect sensitive files automatically in a short time and the support for secure file sharing across devices. All operations in the safe directory are monitored in real time and the files in the directory are protected automatically. Experimental results show that proposed mechanism performs well in performance.

Aiming at the low efficiency in current architectures of digital watermarking, it provides a new architecture—asymmetric digital watermark. This architecture has the third trusted party as the center. And by using two watermarks(secret watermark and public watermark)and “watermark browser”, users can independently extract and display the intellectual property information hidden in the digital multimedia. It not only makes the intellectual property information public, but also highly improves the efficiency. In the results, this architecture can protect the intellectual property of creators, avoid users from unauthorized use, and regular the authentication and the management of the intellectual property.