Japan Airlines Corp. said Thursday that code numbers to enter restricted areas at 16 domestic airports and the Guam airport of the United States have been leaked and publicized on the Internet.

The 17 different codes, including those for Narita and Haneda airports, were held in a personal computer owned by a 29-year-old JAL copilot, whose name is being withheld.

The computer was infected by a virus and the codes were leaked to data flows being exchanged through file-sharing software over the Internet, the nation's largest airline said.

Twelve of the 17 airports will change their key codes by the end of Friday, and JAL has asked Guam to do so, too, the carrier said.