Mega is expected to use encryption methods which will mean only users will know what they are uploading.
It will be decided in March whether Mr Dotcom should be extradited from New Zealand to the US to face charges relating to copyright theft.
The 38-year-old said he would launch Mega on 20 January 2013 — a year to the day since his arrest.
By keeping details of files uploaded on Mega secret from the site's administrators, Mr Dotcom said he believed this would mean the site was not in violation of US laws. "The new Mega will not be threatened by US prosecutors," he said.
"The new Mega avoids any dealings with US hosters, US domains and US backbone providers and has changed the way it operates to avoid another takedown."