The Invention Secrecy Act of 1951 (Pub. L. 82–256, 66 Stat. 3, enacted February 1, 1952, codified at 35 U.S.C. ch. 17) is a United States federal law that authorizes the government to suppress disclosure of certain inventions for reasons of national security. The statute empowers selected federal agencies to decide whether a patent application poses a risk and to compel its classification under secrecy orders. In practice, secrecy orders have been imposed not only on inventions affecting military defense but also on those alleged to threaten economic stability, with critics noting that many such restrictions rest on speculative or unproven harms. The law applies broadly to all inventions in the United States for which a patent is filed or granted (35 U.S.C. § 181). Every patent application is reviewed, and thousands of inventions are manually screened each year. Any federal agency with “classifying powers” can order a restriction under the Act.

Tl;Dr The Invention Secrecy Act is a US federal law authorizing the government to suppress disclosure of certain inventions for reasons of national security. 6,543 inventions are currently suppressed.