Edward Felten, the Princeton computer science professor who has been at the centre of some controversy in the US due to a paper he wrote detailing ways to crack the encryption in the SDMI digital music system, chose not to present his findings at a conference on Thursday last week.

Felten decided not to publish the paper after a threatened lawsuit by the SDMI (Secure Digital Music Initiative), the RIAA (Recording Industry Association of America) and Verance, the maker the one of the SDMI's encryption technologies, according to a statement posted Thursday on Felten's website.

Lawsuits were also threatened against the conference organisers and their employers, the statement said. The paper was to have been presented at the Information Hiding Workshop, held from 25 to 27 April in Pittsburgh.

The statement ends: "We look forward to the day when we can present the results of our research to you, our colleagues, through the normal scientific publication process, so that you can judge our work for yourselves."

SDMI is the name of both the technology and the organisation, made up of around 300 computer, electronics and entertainment companies which are working to create secure, copyright-friendly digital music.

Felten's website can be found here, and the full text of Felten's paper can be read online here.