Multimedia data and information systems manage, communicate, and present multimedia data including text, images, audio and video. The authors need to ensure that the data is protected from unauthorized access as well as malicious corruption. Digital watermarking techniques that insert hidden copyright messages into the multimedia data are needed. Furthermore, since multimedia data is being used for security applications such as surveillance and monitoring, protecting privacy of the individual is crucial. This paper will discuss the security of multimedia systems using access control policies.