ABSTRACT
This chapter describes the discussion of authenticating multimedia content based on digital signature schemes, although digital watermarking techniques might be employed in some specific schemes. It examines the techniques from multimedia processing and analysis, security and cryptography, communication and coding and introduces the basic concepts and unifying the technical terms. Complete authentication refers to directly applying the crypto signature scheme to multimedia data authentication. Multimedia authentication is a relatively new research area compared to other “traditional” research areas such as multimedia compression. Content authentication includes fragile authentication and semifragile authentication. The semifragile content authentication mode is usually selected for those applications demanding more robustness, such as wireless communication. Content authentication was further classified into fragile authentication and semifragile authentication, based on the robustness of authentication. The chapter discusses a good semifragile authentication system should not only be secure enough to the malicious attacks, but also be robust enough to the acceptable manipulations. Such a good system should be application dependent.
