Whoever, by virtue of his employment by the United States, obtains from another or has or has had custody of or access to, any official diplomatic code or any matter prepared in any such code, or which purports to have been prepared in any such code, and without authorization or competent authority, willfully publishes or furnishes to another any such code or matter, or any matter which was obtained while in the process of transmission between any foreign government and its diplomatic mission in the United States, shall be fined under this title or imprisoned not more than ten years, or both.