In a forensic watermarking architecture, a buyer-seller protocol protects the watermark secrets from the buyer and prevents false infringement accusations by the seller. Existing protocols encrypt the watermark and the content with a homomorphic public-key cipher and perform embedding under encryption. When used for multimedia data, these protocols create a large computation and bandwidth overhead. In this correspondence, we show that the same functionality can be achieved efficiently using recently proposed secure watermark embedding algorithms.

This paper presents a security architecture for a pay-TV conditional access system, assuming the most challenging scenario from a designer's point of view; a pay-per-view business model in a broadcast-only environment. The starting point for the security architecture is a broadcast encryption scheme and a queueing network for injecting conditional access messages into the broadcast stream. Design constraints related to a conditional access client are taken into account in the design of the architecture, as well as a maximum amount of bandwidth available for the transmission of conditional access messages. In addition, commercial design objectives like quick content access and quick client activation are also addressed. A substantial part of the paper is devoted to the design and analysis of an efficient injector model based on queueing theory, defining the strategy for injecting conditional access messages into the broadcast stream. A numerical example with real-world values of the parameters is used to demonstrate the effectiveness of the presented approach.

Helleseth, Kim and No (2003) described the linear complexity over F/sub p/ of Sidel'nikov sequences of length p/sup m/ -1 for p = 3, 5 and 7. This result is generalized to all odd primes.

Helleseth, Kim, and No (2003) described the linear complexity over F/sub p/ of Sidel'nikov sequences of length p/sup m/-1 for p=3, 5, and 7. In this correspondence, the result is generalized to all odd primes.