------------------------------------------------------------------------------ B O S T O N U N I V E R S I T Y Computer Science Department C O L L O Q U I U M Wednesday, December 11, 1996 3:00 pm (Coffee served at 2:30 pm, Room MCS 137) Room MCS 135 ------------------------------------------------------------------------------ ASYMMETRIC AND ANONYMOUS FINGERPRINTING Birgit Pfitzmann Univ. Hildesheim Institut fur Marienburger Platz 22 D 31141 Hildesheim Germany pfitzb@informatik.uni-hildesheim.de Fingerprinting is one type of measures for the copyright protection of digital data. The merchant sells a slightly different 'copy' to each buyer so that he can later identify the original buyer of an illegally redistributed copy. All previous fingerprinting schemes are symmetric in the following sense: Both the buyer and the merchant know the fingerprinted copy. Thus, when the merchant finds this copy somewhere, there is no proof that it was the buyer who put it there, and not the merchant. We introduce and construct asymmetric fingerprinting schemes, where only the buyer knows the fingerprinted copy and the merchant, upon finding it somewhere, can find out and prove to third parties whose copy it was. Another problem with fingerprinting arises in the context of electronic marketplaces where untraceable electronic cash offers buyers privacy similar to that when buying books or music in normal shops with normal cash. Now buyers would have to identify themselves for fingerprinting. To remedy this, we introduce and construct anonymous asymmetric fingerprinting schemes, where buyers can buy information anonymously, but can nevertheless be identified if they redistribute this information illegally. Host: Prof. Leonid Levin ------------------------------------------------------------------------------ For colloquium info, including directions, see http://www.cs.bu.edu/colloquium For more information contact Prof. David Yates ------------------------------------------------------------------------------