Now showing 1 - 10 of 46
  • Publication
    Digital signatures based on invertible watermarks for video authentication
    ( 2005)
    Hauer, E.
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    Dittmann, J.
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    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
    Digitale Audiowasserzeichen im Archivbereich - Das H2O4M Projekt
    ( 2003)
    Steinebach, M.
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    Hauer, E.
    ;
    Dittmann, J.
  • Publication
  • Publication
    Watermarking protocols for authentication and ownership protection based on timestamps and holograms
    ( 2002)
    Dittmann, J.
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    Steinebach, M.
    ;
    Ferri, L.C.
    Digital watermarking has become an accepted technology for enabling multimedia protection schemes. One problem here is the security of these schemes. Without a suitable framework, watermarks can be replaced and manipulated. We discuss different protocols providing security against rightful ownership attacks and other fraud attempts. We compare the characteristics of existing protocols for different media like direct embedding or seed based and required attributes of the watermarking technology like robustness or payload. We introduce two new media independent protocol schemes for rightful ownership authentication. With the first scheme we ensure security of digital watermarks used for ownership protection with a combination of two watermarks: first watermark of the copyright holder and a second watermark from a Trusted Third Party (TTP). It is based on hologram embedding and the watermark consists of e.g. a company logo. As an example we use digital images and specify the properties of the embedded additional security information. We identify components necessary for the security protocol like timestamp, PKI and cryptographic algorithms. The second scheme is used for authentication. It is designed for invertible watermarking applications which require high data integrity. We combine digital signature schemes and digital watermarking to provide a public verifiable integrity. The original data can only be reproduced with a secret key.
  • Publication
    Combined fingerprinting attacks against digital audio watermarking: Methods, results and solutions
    ( 2002)
    Steinebach, M.
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    Dittmann, J.
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    Saar, E.
    The methods for secure customer identification by digital fingerprinting for audio data are discussed. The algorithms by D. Boneh et al. (Proc. CRYPTO'95, p.452-465, 1995) and Joerg Schwenk et al. (Proceedings of SPIE, vol. 3657, p.24-29, Jan. 1999) are discussed and are then combined with an audio watermarking algorithm for practical evaluation of their coalition resistance to detect illegal copies. Test results are provided and the security performance against different types of coalition attacks is evaluated.
  • Publication
    Audio watermarking quality evaluation: Robustness to DA/AD processes
    ( 2002)
    Steinebach, M.
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    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
    StirMark Benchmark: Audio watermarking attacks based on lossy compression
    ( 2002)
    Steinebach, M.
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    Lang, A.
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    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
    Ausgewählte Angriffe der Stirmark Benchmark Suite
    ( 2002)
    Lang, A.
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    Thiemert, S.
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    Steinebach, M.
    ;
    Dittmann, J.
  • Publication
    Innovative Geschäftsmodelle auf der Basis digitaler Wasserzeichen
    ( 2002)
    Kratz, G.
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    Steinebach, M.
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    Dittmann, J.