Defensive publications: the third option for protecting an invention
It gives you no rights of your own, but it stops anyone else from patenting your idea.
Published
Author
Sam Redford, PhD
Patent Principal
Sam previously filed and prosecuted patents at Mintz and Morrison Foerster. He received his PhD in immunology from UCSD on the interactions between immune cells and lipid metabolism during chronic parasitic infection.
Defensive publications: the third option for protecting an invention
Most inventors know the choice between patenting an invention and keeping it a trade secret. Fewer know there is a third option. A defensive publication is a dated public description of your invention, put out on purpose so nobody else can patent it later. It gives you no rights of your own, but it stops a competitor, a supplier, or a patent assertion entity from patenting your idea and then demanding royalties or suing you for using it. It costs a small fraction of what a patent does, has no ongoing fees, and can be live within days.
There is a catch. A publication only protects you if it’s detailed enough, published where patent examiners actually look, and is out before anyone else files. Publishing is also permanent, so once your description is public you generally lose the chance to patent the invention yourself. And it hands competitors a full account of your work, which is why it suits some inventions much better than others.
The full guide explains how to write a publication that holds up, compares it with patents and trade secrets on cost, speed, and protection, and gives two questions that settle most hardware decisions. It also shows how a typical hardware company ends up using all three approaches at once.