Fraunhofer Institut für Integrierte Publikations-und Informationssysteme IPSI

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  • Publication
    Digital signatures based on invertible watermarks for video authentication
    ( 2005)
    Hauer, E.
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    Dittmann, J.
    ;
    Steinebach, M.
  • Publication
    A high-capacity block based video watermark
    ( 2004)
    Thiemert, S.
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    Vogel, T.
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    Dittmann, J.
    ;
    Steinebach, M.
  • Publication
    Advanced audio watermarking benchmarking
    ( 2004)
    Dittmann, J.
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    Steinebach, M.
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    Lang, A.
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    Zmudizinski, S.
    Digital watermarking is envisaged as a potential technology for copyright protection and manipulation recognition. A key issue in the usage of robust watermarking is the evaluation of robustness and security. StirMark Benchmarking has been taken to set a benchmarking suite for audio watermarking in addition to existing still image evaluation solutions. In particular we give an overview of recent advancements and actual questions in robustness and transparency evaluations, in complexity and performance issues, in security and capacity questions. Further more we introduce benchmarking for content-fragile watermarking by summarizing design aspects and concluding essential benchmarking requirements.
  • Publication
    Digitale Audiowasserzeichen im Archivbereich - Das H2O4M Projekt
    ( 2003)
    Steinebach, M.
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    Hauer, E.
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    Dittmann, J.
  • Publication
    Capacity-optimized mp2 audio watermarking
    ( 2003)
    Steinebach, M.
    ;
    Dittmann, J.
    Today a number of audio watermarking algorithms have been proposed, some of them at a quality making them suitable for commercial applications. The focus of most of these algorithms is copyright protection. Therefore, transparency and robustness are the most discussed and optimised parameters. But other applications for audio watermarking can also be identified stressing other parameters like complexity or payload. In our paper, we introduce a new mp2 audio watermarking algorithm optimised for high payload. Our algorithm uses the scale factors of an mp2 file for watermark embedding. They are grouped and masked based on a pseudo-random pattern generated from a secret key. In each group, we embed one bit. Depending on the bit to embed, we change the scale factors by adding 1 where necessary until it includes either more even or uneven scale factors. An uneven group has a 1 embedded, an even group a 0. The same rule is later applied to detect the watermark. The group size can be increased or decreased for transparency/payload trade-off. We embed 160 bits or more in an mp2 file per second without reducing perceived quality. As an application example, we introduce a prototypic Karaoke system displaying song lyrics embedded as a watermark.
  • Publication
  • Publication
    Ausgewählte Angriffe der Stirmark Benchmark Suite
    ( 2002)
    Lang, A.
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    Thiemert, S.
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    Steinebach, M.
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    Dittmann, J.
  • Publication
    StirMark Benchmark: Audio watermarking attacks based on lossy compression
    ( 2002)
    Steinebach, M.
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    Lang, A.
    ;
    Dittmann, J.
    StirMark Benchmark is a well-known evaluation tool for watermarking robustness. Additional attacks are added to it continuously. To enable application based evaluation, in our paper we address attacks against audio watermarks based on lossy audio compression algorithms to be included in the test environment. We discuss the effect of different lossy compression algorithms like MPEG-2 audio Layer 3, Ogg or VQF on a selection of audio test data. Our focus is on changes regarding the basic characteristics of the audio data like spectrum or average power and on removal of embedded watermarks. Furthermore we compare results of different watermarking algorithms and show that lossy compression is still a challenge for most of them. There are two strategies for adding evaluation of robustness against lossy compression to StirMark Benchmark: (a) use of existing free compression algorithms (b) implementation of a generic lossy compression simulation. We discuss how such a model can be implemented based on the results of our tests. This method is less complex, as no real psycho acoustic model has to be applied. Our model can be used for audio watermarking evaluation of numerous application fields. As an example, we describe its importance for e-commerce applications with watermarking security.
  • Publication
    Audio watermarking quality evaluation: Robustness to DA/AD processes
    ( 2002)
    Steinebach, M.
    ;
    Lang, A.
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    Dittmann, J.
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    Neubauer, C.
    Audio watermarking has become an important technology for the recording and advertisement industry. Today's embedding and detection strategies often rely on digital/ high quality channels, like CD or mp3. However for numerous applications, watermarks surviving noisy analog environments are better suited or even required. Using such schemes allows to identify, audio signals with monitoring devices which are 'listening' to the incoming signals. In the same way, illegal recordings of concerts can be identified. In this paper we describe a test environment for noisy, acoustic, (analog) channels and present results obtained from a particular watermarking scheme. We identify changes in the affected audio material, like frequency response or the amount of noise added to the signal. In order to do automatic robustness evaluations of watermarking schemes, the Stirmark Benchmark environment can be used. We analyze if it is possible to simulate an acoustic, noisy DA/AD environment with filters, quantization and noise generators. Based on the presented test results, we identify the parameters relevant for watermarks to successfully survive noisy acoustic channels and thereby provide valuable hints for audio watermark designers. We also describe a design concept for a DA/AD simulation.
  • Publication
    Innovative Geschäftsmodelle auf der Basis digitaler Wasserzeichen
    ( 2002)
    Kratz, G.
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    Steinebach, M.
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    Dittmann, J.