On October 27, 1977, Dr. Gerald F. Ross filed a patent application for a new invention he had devised to defeat the jamming of electromagnetic transmissions at specified frequencies. But it was not until June 17, 2014 — nearly 37 years later — that his patent was finally granted (Anti-jam apparatus for baseband radar systems, patent number 8,754,801).

In the interim, Dr. Ross’s patent application had been subject to a secrecy order under the Invention Secrecy Act of 1951, which both prevented issuance of the patent and prohibited its public disclosure.

At the end of Fiscal Year 2014 (on September 30), there were 5,520 such invention secrecy orders in effect, according to statistics released by the U.S. Patent and Trademark Office under the Freedom of Information Act.

That is the highest number of invention secrecy orders in effect since 1994. It is unclear whether this reflects growing innovation in sensitive technology areas, or a more restrictive approach to disclosure by government agencies.

In fact, the overwhelming majority of current secrecy orders were issued in prior years, but there were 97 new secrecy orders that were imposed in FY 2014. Meanwhile, there were 22 existing orders that were rescinded, including the order concerning Dr. Ross’s invention.

Under the Invention Secrecy Act, secrecy orders may be imposed whenever, in the judgment of an executive branch agency, the disclosure of a patent application would be “detrimental to the national security.” This is a lower, less demanding standard than that for national security classification (which applies to information that could “cause damage to national security”) and not all secret inventions are classified. Some may be unclassified but export controlled, or otherwise restricted.

Other newly disclosed inventions formerly subject to a secrecy order that was rescinded by the government during the past year include these (according to data obtained from the Patent and Trademark Office):

Method of producing warheads containing explosives, patent number 8,689,669

Method of treating a net made from ultra-high-molecular-weight polyethylene, patent number 8,808,602

Ballistic modification and solventless double propellant, and method thereof, patent number 8,828,161

Ballistic modifier formulation for double base propellant, patent number 8,864,923

Synthetic aperture radar smearing, patent number 8,836,569