Now showing 1 - 10 of 48
  • 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
    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
    Digitale Audiowasserzeichen im Archivbereich - Das H2O4M Projekt
    ( 2003)
    Steinebach, M.
    ;
    Hauer, E.
    ;
    Dittmann, J.
  • Publication
  • Publication
    Anforderungen an digitale Transaktionswasserzeichen für den Einsatz im e-Commerce
    ( 2002)
    Steinebach, M.
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    Dittmann, J.
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    Neubauer, C.
  • Publication
    Watermarking protocols for authentication and ownership protection based on timestamps and holograms
    ( 2002)
    Dittmann, J.
    ;
    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
  • Publication
    Combined fingerprinting attacks against digital audio watermarking: Methods, results and solutions
    ( 2002)
    Steinebach, M.
    ;
    Dittmann, J.
    ;
    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.