The Invention Secrecy Act of 1951 (, codified at 35 U.S.C. §§ 181–188) is a body of United States federal law designed to prevent disclosure of new inventions and technologies that, in the opinion of selected federal agencies, present a possible threat to the national security of the United States. The types of inventions classified under this Act are themselves secret, but most of the inventions which are now no longer secret but once were secret have been in areas with high military significance, such as cryptography and weapons development.