There Are Thousands of Inventions the Government Doesn’t Want You to See. A Shady Law Is Hiding Them.

6 min readA Cold War-era law called the Invention Secrecy Act of 1951 allows U.S. government agencies to suppress patents deemed threats to national security, fueling decades of conspiracy theories about hidden world-changing inventions like the legendary “water engine.”The Invention Secrecy Act lacks clear accountability measures and vaguely defines what constitutes “national security,” making it theoretically possible for the government to suppress inventions to protect corporate interests, though no credible evidence proves this has occurred.In fiscal year 2025 alone, over 6,500 patents were subjected to secrecy orders under the act—more than half the total suppressed during all of World War II—raising questions about whether the government is applying the law too broadly.It’s a right of passage for a particular kind of person, what the young folks call a “canon event,” to hear about the “water engine.” Maybe you first heard it working in a garage with that uncle who listened to a lot of those fringe radio shows. Maybe it was from a friend’s older brother whose room was full of blacklight posters and the scent of incense. Maybe it was a podcast you listened to featuring a guy who used to do stand-up comedy in the ’90s.Whatever the source, at some point you’ll hear about a guy who invented an engine that runs on water (or sometimes a different clean, renewable resource). This engine was going to change the world, bring about a new age, and also make its inventor very, very rich. The details about the person who invented it vary, but the story always has one constant: the U.S. government swept in, stole the invention, and shut the whole operation down—all to protect the interests of the oil industry.This sure sounds like a conspiracy theory whose validity hinges on how much you personally want to believe the government is a shadowy cabal that inhibits human progress to protect its interests. The thing about it is, while no credible evidence exists that the government ever suppressed the existence of a water engine, there’s a real law on the books that makes urban legends like that one entirely plausible.It’s called the Invention Secrecy Act of 1951 (Pub. L. 82-256, 66 Stat. 3), and if you’re an American inventor whose work involves anything like cryptography, weaponry, or energy, it’s a law that hangs over your head like the Sword of Damocles. A remnant of the Cold War, the law allows agencies within the U.S. Government to interject during a patent review process and suppress any inventions that the agency deems a “threat to national security.”It’s easy to see why such a law was conceived. An earlier version existed during both World Wars, where innovations in defense technology ranging from radar to the Manhattan Project required absolute secrecy. When the U.S. government determined that their latest enemy, the Soviet Union, relied on a strategy that combined military might with the covert destabilization of the United States domestically, a great deal of legislation was passed in the interest of “national security,” including the Invention Secrecy Act.To be clear, the law doesn’t simply give the government carte blanche to permanently lock away the fruits of an inventor’s labor and leave them in the poor house on a whim. Under the parameters of the law, agencies ranging from the Department of Defense to NASA can issue a “secrecy order” on patents under review that they feel contain sensitive information. But those secrecy orders are only meant to last for a single year, after which they’re subject to review to determine if the blocked patent still needs to be withheld. The inventors are even entitled to financial compensation if it’s determined that their livelihood is impacted by withholding the patent.But that’s how it appears on paper. In practice, the ambiguity of the law creates an obtuse and fairly convoluted process for the impacted inventors. What constitutes “sensitive information” as it applies to national security? How does one even define “national security?” Is it strictly related to military defense, or could economic concerns also be a matter of national security? If so, couldn’t one argue that an invention that could upend a major industry, even if it ostensibly benefited the consumer, could be a matter of “national security” from an economic perspective? What governmental body gets to make that argument, and what governmental body gets to determine if that argument is valid?To date, no evidence has emerged to prove that agencies within the U.S. government have deliberately used the Invention Secrecy Act to deliberately suppress any inventions in defense of any specific business interests. But the trouble is, the law in its current form makes it possible to do so, and it’s not at all apparent what measures are in place, if any, to prevent that from happening.If your patent were suppressed under the Invention Secrecy Act, could you turn to the courts? Maybe—in theory. But the challenge becomes how to prove that the government wrongfully buried your invention in secrecy if you can’t legally discuss it with anyone.This conundrum was actually tested in court a few years after the law was enacted. There isn’t a wide array of verified (key word: verified) names of inventors directly impacted by the Invention Secrecy Act, but of those, Otto Halpern had arguably the greatest impact in attempting to slay the Nimean Lion that is the ISA.As reported at the time in the Columbia Missourian, physicist Otto Halpern tried to take the government to court over the suppression of a radar-related device he invented in 1941. Initially, the government tried to argue that no suits related to the ISA could proceed until such time as the specific secrecy order was rescinded. Essentially, if an inventor wanted to take the government to court to question the appropriateness of the application of the secrecy order, the government argued that it couldn’t be questioned until the secrecy order was lifted. Since only the government determined when the secrecy order could be lifted, they could in theory delay any suit indefinitely.The government’s argument was that any trial naturally risked exposing the national secrets they were charged by the ISA to defend, but the United States Court of Appeals for the Second Circuit disagreed. The court determined that such proceedings could go forward, provided that the trial occurred in camera, meaning in private, and that it wouldn’t expose national secrets to the public. Rather than allow a trial to proceed, the government ultimately settled with Halpern, furnishing him with $340,000 (roughly $3.9 million in 2026) and a Department of Defense Medal, per his terms.Halpern’s case is one of the very rare instances where a name can be attached to an ISA-impacted patent, and compared to the total number of total patents filed in the U.S. in a given year, there aren’t many of them. Of the more than 788,000 patents filed in Fiscal Year 2025, 6,543 of them were restrained by ISA. However, that’s still more than half of the patents impacted by secrecy orders during the entirety of World War II, and one can’t help but wonder if the government is being, perhaps, overzealous in its application of the ISA, or overly broad in its definition of national security compared to the World War II era.The inherent secrecy of the ISA, paired with its apparent lack of accountability, has made it fodder for a bevy of conspiracy theories over the years. Advocates of the “free energy movement,” a pseudoscientific school of thought that believes forms of pollution-free or zero-cost energy already exist but are being suppressed, often incorporate the ISA into their arguments. After all, if the government will neither confirm nor deny if someone’s patent is on the secret list, anyone can claim they have a brilliant, game-changing energy invention that’s locked away behind the ISA. If an inventor died in poverty, or under mysterious circumstances, all the better to fuel the narrative of the conspiracy (as such, Nikola Tesla is also sometimes incorporated as a martyr of governmental invention-suppression, especially since the government did swoop in to confiscate his papers shortly after he died).There is, it should be stressed, no credible evidence to suggest that the government has ever used the ISA to deliberately drive any inventors into poverty, let alone actively assassinate anyone over an invention. There’s no evidence to even suggest that any of the 6,543 inventions given secrecy orders under the ISA in 2025 are even close to the kind of miracle cure, perpetual motion, or cold fusion-generating machines the fringe parts of the internet imagine they are.The trouble is, there inarguably are 6,543 inventions that the U.S. government very pointedly doesn’t want you, the public, to know about. And there’s no real way to find out what they are, or why they were withheld for “national security.” So what you decide those 6,543 inventions might ultimately be hinges on how much you personally want to believe the government is a shadowy cabal that inhibits human progress to protect its interests.Michale Natale is a News Editor for the Hearst Enthusiast Group. As a writer and researcher, he has produced written and audio-visual content for more than fifteen years, spanning historical periods from the dawn of early man to the Golden Age of Hollywood. His stories for the Enthusiast Group have involved coordinating with organizations like the National Parks Service and the Secret Service, and travelling to notable historical sites and archaeological digs, from excavations of America’ earliest colonies to the former homes of Edgar Allan Poe.