Trouble with Prime Numbers: Decss, Dvd and the Protection of Proprietary Encryption Tools

Abstract

The DVD video format has become one of the most important developments in the home entertainment market since the popularisation of the magnetic video recording. The film industry delivered this format with a built in security system which was supposed to avoid illegal copying of the discs, much as what is taking place with the music CD and the almost indiscriminate copying of music into MP3 format over the Internet. This was achieved by means of encryption technology. This essay deals with the cracking of DVD encryption and its further diffusion as a computer programme named DeCSS, which has been made available over the Internet in various formats, including t-shirts and a numerical representation of the code. There are three court cases based on the online posting of this programme, two in the United States and one in Norway. The article starts by describing the technology involved, as it is felt by the author that some of these technical issues are of importance to the legal implications of the case and should be understood properly. The article then deals with the developments in all of the three cases up to this date. The essay then finishes with a look at the legal issues involved, including hyper-linking, trade secrets, freedom of speech and the translation of DeCSS into numerical format.

Keywords: DVD, DeCSS, DMCA, Europe, Copyright Directive, encryption

JEL Classification: K19