U.S. attorneys have filed an emergency motion to stay a federal judge's order in a closely watched court action challenging the government's restrictions on the export of encryption, an attorney involved in the case said. The move has been expected since the judge ruled August 25 that a University of Chicago professor may post his encryption program on the Internet. The Justice Department's motion argues that the ruling is so threatening to national security that it should be entirely blocked pending an appeal. Shortly after issuing her injunction, the federal judge stayed major portions of it. It is the remaining sections of the injunction that the government now is attempting to block.