Jean-Paul M. G. Linnartz

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In biometrics, a human being needs to be identified based on some characteristic physiological parameters. Often this recognition is part of some security system. Secure storage of reference data (i.e., user templates) of individuals is a key concern. It is undesirable that a dishonest verifier can misuse parameters that he obtains before or during a(More)
If C is a q-ary code of length n and a and b are two codewords, then c is called a descendant of a and b if ci 2 fai; big for i = 1; : : : ; n. We are interested in codes C with the property that, given any descendant c, one can always identify at least one of the `parent' codewords in C. We study bounds on F (n; q), the maximal cardinality of a code C with(More)
In some applications of electronic watermarks, the device that detects whether content contains a watermark or not is in public domain. Attackers can misuse such detector as an oracle that reveals up to one bit of information about the watermark in each experiment. An information-theoretical analysis of the information leakage is provided, and a method is(More)
The prospect of consumer digital versatile disk (DVD) recorders highlights the challenge of protecting copyrighted video content from piracy. We describe the copy protection system currently under consideration for DVD. The copy protection system broadly tries to prevent illicit copies from being made from either the analog or digital I/O channels of DVD(More)
In orthogonal frequency-division multiplexing, time variations of a multipath channel lead to a loss of orthogonality between the subcarriers, and thereby limit the achievable throughput. This paper proposes a general framework for a controlled removal of intercarrier interference (ICI) and channel acquisition. The core idea behind our method is to use a(More)
In mobile reception, the reliability of orthogonal frequency division multiplexing (OFDM) is limited because of the time-varying nature of the channel. This causes intercarrier interference (ICI) and increases inaccuracies in channel tracking. In this paper, we model the ICI using derivatives of the channel amplitude. This allows us to design a relatively(More)
Watermarks allow embedded signals to be extracted from audio and video content for a variety of purposes. One application is for copyright control, where it is envisaged that digital video recorders will not permit the recording of content that is watermarked as “never copy”. In such a scenario, it is important that the watermark survive both normal signal(More)