An overview of streamed data authentication techniques
In the chapter we present some of the techniques proposed for authenticating digital streams. We start with the so-called block signatures, where every packet contains full information needed for its authentication. Then, we describe two techniques based on a simple hash chain for an off-line authentication and its modification where one-time signatures are used for an on-line authentication. Later, we consider the TESLA scheme for authenticating streams in case of synchronous systems. This is followed by augmented hash chains with signature packets used once per a sequence of packets rather than for the whole stream. The chapter is concluded with a short comparison of the considered techniques.