A hacker known for cracking the copy-protection technology in DVDs claims to have unlocked the playback restrictions of Apple Computer Inc.’s iPod and iTunes music products and plans to license his code to others.

The move by Jon Lech Johansen, also known as “DVD Jon,” could pit the 22-year-old against Apple’s lawyers, experts say, but if successful could free users from some restrictions Apple and its rivals place on digital music.