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

Wolfgang Spinnler

Juergen Herre

Stefan Kraegeloh

Joerg Pickel

Christian Neubauer

Frank Siebenhaar

Ralph Kulessa

Patrick Aichroth

Stefan Krägeloh

Jörg Pickel

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

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Erlangen, Germany

Wolfgang Spinnler