Digital watermarking-based authentication techniques for real-time multimedia communication

Data integrity and source origin authentication are essential topics for real-time multimedia systems. But the traditional methods are not very applicable to overcome the distortion introduced in multimedia data transportation. In this thesis some security mechanics are proposed, which rely on authentication rather than on encryption methods. The highly asymmetric architectures found in ubiquitous computing applications are exploited to provide a protection of the transmitted multimedia data by means of well-known digital watermarking techniques. The advocated approach adopts public key encryption to efficiently generate non-repudiate multimedia data, whereas both the digital watermark generation and the authentication algorithms are public.