Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Musictrace Gmbh

Ralph Kulessa

Christian Neubauer

Frank Siebenhaar

Stefan Kraegeloh

Joerg Pickel

Wolfgang Spinnler

Juergen Herre

Patrick Aichroth

Stefan Krägeloh

Jörg Pickel

Sascha Disch

Jürgen Herre

Harald Popp

Marc Gayer

Karsten Linzmeier

Jens Hasselbach

Stefan Puchta

Kurt Michael Krauss

For monitoring a data transmitter such as a streaming server, which supplies transmitted data in response to a request of a receiver, an examiner examines a data traffic at the input of a receiver or at the output of the receiver, the examiner being configured to ascertain whether the data traffic falls below a minimum threshold. If the minimum threshold is fallen below, a connection activator initiates a new connection between the receiver and the data transmitter. This serves to enable consistent data-transmitter monitoring, even for non-reliable point-to-point connections via the internet.

Apparatus and method for monitoring data transmitter

The present invention relates to a device for detecting a manipulation of an information signal, having an extractor for extracting an information signal component characteristic for the information signal from the information signal, an encrypter for encrypting the information signal component to obtain an encrypted signal, and a comparator for comparing the encrypted signal to a reference signal, wherein the reference signal is an encrypted representation of a non-manipulated reference signal component of a reference information signal to detect the manipulation.

Device and method for detecting a manipulation of an information signal

The present invention relates to a device for detecting a manipulation of an information signal, having an extractor for extracting an information signal component characteristic for the information signal from the information signal, an encryptor for encrypting the information signal component to obtain an encrypted signal, and a comparator for comparing the encrypted signal to a reference signal, wherein the reference signal is an encrypted representation of a non-manipulated reference signal component of a reference information signal to detect the manipulation.

For embedding watermark information into an information signal including audio and/or video information, first of all a synchronization sequence with a plurality of synchronization sequence units and a data sequence with a plurality of data sequence units are provided, wherein between the data sequence and the synchronization sequence a time shift is present and wherein a degree of shifting depends on the watermark information. A combination means generates a combination sequence having a plurality of combination sequence units from the synchronization sequence and the data sequence shifted with regard to the synchronization sequence, wherein the combination sequence units are derived from synchronization sequence units and shifted data sequence units. The combination sequence is combined with the information signal in order to embed the watermark information into the information signal. A watermark extractor receives a synchronization sequence correlation peak for every data sequence correlation peak associated with the same and therefore determines the watermark information on the basis of the time interval between the synchronization sequence correlation peak and the data sequence correlation peak in a secure and robust way. The concept is robust, provides a high data rate and is simultaneously flexible with regard to the weighting of synchronization energy and data energy and with regard to the robustness on the one hand and data rate on the other hand, respectively.

Method and device for embedding watermark information and method and device for extracting embedded watermark information

According to an inventive scheme for introducing a watermark into an information signal, the information signal is at first transferred from a time representation to a spectral/modulation spectral representation). The information signal is then manipulated in the spectral/modulation spectral representation in dependence on the watermark to be introduced to obtain a modified spectral/modulation spectral representation, and subsequently an information signal provided with a watermark is formed based on the modified spectral/modulation spectral representation. An advantage is that, due to the fact that the watermark is embedded and/or derived in the spectral/modulation spectral representation or range, traditional correlation attacks as are used in watermark methods based on a spread-band modulation cannot succeed easily.

Watermark embedding

Prior to embedding a watermark in an audio signal, a spectral representation of the audio signal and a spectral representation of the watermark signal are determined. The spectral representation of the watermark signal is then processed on the basis of a psychoacoustic masking threshold of the audio signal. The processed watermark signal is combined with the audio signal to obtain an audio signal bearing a watermark. The spectral representation of the watermark signal is processed iteratively as follows: first a predetermined watermark initial value is selected, then the interference introduced into the spectral representation of the audio signal after a quantization of the spectral representation of the audio signal is determined and then, if the interference introduced by the watermark initial value exceeds the predetermined interference threshold, the watermark initial value is modified progressively until the resulting interference introduced into the spectral representation of the audio signal after quantization is less than or equal to the predetermined interference threshold. The modified watermark initial value at the end of the iteration is used as the processed watermark signal to be combined with the audio signal. As a result it is no longer possible for a watermark to be quantized out. Instead, full control over the energy of the watermark is achieved. A watermark can therefore be embedded in an audio signal to provide either the best possible degree of watermark detectability or the best possible audio quality.

Device and method for embedding a watermark in an audio signal

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Feucht, Germany

Ralph Kulessa