Providing security for multimedia data has become an important issue for individuals, companies and governments. Traditional cryptographic methods formultimedia security tend to add a significant amountof overhead to achieve quality encryption levels.This additional overhead is not conducive to processing large amounts of data in real-timeapplications. Recursive sequence based multimediaencryption theory can meet the stringent performancerequirements for real-time multimedia applications,while achieving different levels of security. Thisbook focuses on presenting efficient encryption approaches that are suitable for real-time applications. It is intended to be used byindividuals interested in privacy, copyrightprotection, and security of digital information. Features: (1) Present a straightforward multimedia encryption system that can encrypt different types of multimedia data using different key-dependant recursive sequences. (2) Present multimediaencryption techniques using general 2D or 3D recursive sequence transforms. (3) Analyze and compare security issues of several multimedia encryption methods based on recursive sequences.