Kim Dotcom has just revealed plans to relaunch a new and improved, “raid-proof” successor to his Megaupload service, exactly a year after the original site was shut down by US authorities.

Rumors surrounding Megaupload’s second-coming have been doing the rounds for some time, but now the New Zealand-based entrepreneur has finally lifted the lid on his plans to usurp the authorities, announcing a launch date of January 19, 2013.

At the height of its popularity, the original incarnation of Megaupload attracted somewhere in the region of 50 million hits a day, and was backed by dozens of big names in the music industry.

Dotcom, who is currently battling against extradition to the US on charges of copyright violation, revealed on Twitter that the new site – Mega – will be launched at a special press conference in which he plans to showcase a mock ‘doomsday’ button that the FBI alleges was in place to shut down the original site if it was raided:

“ANNOUNCEMENT: The new Mega will launch exactly 1 year after the raid with a #MansionPressConference & #DoomsdayLaunchButton,”

Dotcom said that the new and improved Mega will be bolstered by a special encryption key that Mega itself doesn’t have access to – the idea being that instead of him being in control, users and third-party app developers will be the ones in charge of file access.

Interviewed by Wired magazine, Dotcom explains:

“If servers are lost, if the government comes into a data center and rapes it, if someone hacks the server or steals it, it would give him nothing. Whatever is uploaded to the site, it is going to be remain closed and private without the key.”

Dotcom said that he envisions Mega expanding far beyond its original role of file sharing, with plans for email, video applications and other functions in the works. He adds that a number of investors are already interested in making the venture happen.

According to Dotcom, 90% of the coding for the new site is already done; meanwhile, his lawyers, investors and partners are working out the legalities and intricacies of the project. Dotcom hasn’t yet announced which domain the new Mega will be hosted on, but wherever it goes it’s unlikely to be a .com domain, given his problems with the American authorities.