While hackers now have to sharpen their saws for the remaining three technologies. SDMI was formed to develop a standard for secure music distribution, threatened by the evolution of free music distribution technologies such as MP3 and Naptster. SDMI announced over the weekend that only one of the two attacks was significant because it could be repeated on additional pieces of music. SDMI released the results following weeks of speculation and amid claims by researchers from some American universities and research centers that they had broken into four of the watermarking technologies, which were designed as a guard against hacking by using hidden signals in the files.

SDMI Executive Director Leonardo Chiariglione said the group received 447 submissions in the first round, which ended October 7. A second round began after that date to determine if submissions were repeatable on music or not.

"Whether successful or not, they taught us important lessons about what can and cannot work in the marketplace," Mr Chiariglione said in a statement. There is hope for hackers yet too, as some leading hacker groups boycotted the content. Linux Journal Technology Editor Don Marti had given a boycott call for example. Many groups including some well known hackers from India kept away. Had these hardcore hackers got into the job, the SDMI could have been a total disaster. "Why should we get into the trap of SDMI? We are not duty-bound to participate in its contest. We can hack it as and when it is commercially available," quipped a hacker from a well known Indian group, which is often hired by Indian security agencies.

The SDMI said the technologies that withstood the challenge included both watermark and non-watermark solutions. While SDMI had originally posted six technologies, one proponent withdrew its proposal early in the testing process.

Founding members of the SDMI include big record companies like Seagram Co Ltd's Universal Music, Bertelsmann AG's BMG, Sony Music, Warner Music Group and EMI Music. Mr Marti sponsored a boycott call saying the music industry is trying to use hackers as a "free consulting" service to help it lock down its digital music and prevent people from legally making multiple copies for personal use. The SDMI initiative was launched in the face of rampant music swapping online. Consequently the entertainment industry felt the need to have a technical method of securing digital music.

It sponsored the contest hoping that hackers will help it do that. Using the results of the hacking, SDMI will settle on some standards for inserting the technology into digital content that can only be played on SDMI-compatible consumer electronics devices. The music industry was late to the game of digital music, in part because it underestimated the new technology companies and the power of the Internet to promote songs. Meanwhile, sharing digital files - both legitimate and pirated - has become increasingly popular. Fighting the tide so far, the music industry has tried to fight the tide of digital music trading by using the courts. The Recording Industry Association of America, which is a founding member of the SDMI, has sued many new media companies, including Napster and MP3.com. What's more.

There's really no guaranteed way to maintain complete control over digital music distribution, as much as the industry might wish to. For example, there's always the possibility that technology claiming to be hacker-proof today will be cracked tomorrow.