Can you patent an invention while keeping it secret ?

Every business that develops a technical innovation sooner or later faces the same choice: file a patent application or keep the invention secret. The question is often put more ambitiously: can you patent an invention while keeping it secret? The answer, in principle, is no, because a patent is obtained at the price of disclosure. That answer nonetheless calls for some nuance, which turns on the timetable of the procedure, on the risk of disclosing an invention too early and on the possibility of combining patent and secrecy over distinct elements.

The patent, exclusivity in return for disclosure

How a patent works

A patent is an industrial property right granted by a national office, such as INPI in France, or a regional one, such as the European Patent Office (EPO). It confers on its proprietor an exclusive right of exploitation for a maximum term of twenty years from the filing date. The invention must be new, meaning that it must not have been made available to the public before filing. It must involve an inventive step, in that it does not follow obviously from the prior art for the person skilled in the art, and it must be susceptible of industrial application.

A filing that requires full disclosure

The application comprises a description of the invention, claims that define the scope of protection, an abstract and, where appropriate, drawings. The description must disclose the invention in a manner sufficiently clear and complete for it to be carried out by the person skilled in the art. The application is published, as a rule eighteen months after the filing or priority date, and the invention then becomes accessible to everyone. Publication is the price of the exclusivity conferred by the patent.

Patenting an invention while keeping it secret, an impossibility in principle

It follows that an invention cannot be patented while being kept secret for good. Secrecy survives only for the period preceding publication. An applicant who withdraws the application before the technical preparations for publication are completed may prevent its content from being made public, but thereby gives up protection.

The two forms of protection can, however, be combined over distinct subject matter. A business may patent a product and keep secret a manufacturing know-how that is not needed to carry out the claimed invention. This division calls for rigour: a description that withheld indispensable information would expose the patent to an action for invalidity, or to revocation in opposition proceedings before the EPO, for insufficiency of disclosure.

Disclosing an invention too early, a risk to novelty

Absolute novelty

Under both French and European law, novelty is assessed on an absolute basis. Any disclosure made before filing may be cited against the application, including a disclosure by the inventor. A scientific paper, a demonstration at a trade fair, a presentation to someone who is under no duty of confidentiality or a post on social media may be enough to destroy novelty, and with it any prospect of a patent.

Two narrow exceptions

The European Patent Convention (Article 55 EPC) and the French Intellectual Property Code (Article L. 611-13 CPI) disregard only two situations, provided that the disclosure occurred within the six months preceding filing. The first is a disclosure resulting from an evident abuse in relation to the inventor or the applicant, for example a breach of a confidentiality undertaking or the misappropriation of information. The second is the display of the invention at an official, or officially recognised, international exhibition, which must be declared on filing and supported by a certificate.

These exceptions are construed narrowly and require precise evidence. They in no way permit communication about an invention before filing. The practical rule remains simple: until the application is filed, no disclosure should take place outside a secure legal framework.

Sound practice

Before discussing the invention with an investor, an industrial partner or a service provider, have a non-disclosure agreement (NDA) signed. Then file the application before any public communication. Once the application is filed, disclosure no longer destroys the novelty of what has been filed, since the prior art is assessed at the filing or priority date. Caution is still needed for later improvements, which do not benefit from that date and may be compromised by your own communications.

Secrecy, an alternative to the patent

A strategic choice

Protection through secrecy rests on non-disclosure. It requires neither filing nor fees and may last for as long as the information remains confidential. The French trade secrets regime, set out in the Commercial Code, nevertheless protects only information that derives its commercial value from being secret and that is subject to reasonable protective measures. Secrecy therefore has a cost, that of the organisation required to preserve it.

It suits manufacturing processes that the finished product does not reveal, internal methods, certain algorithms or settings, innovations with a short commercial life, and situations in which the cost of patents exceeds the expected value of exclusivity.

The limits of secrecy

Secrecy confers no exclusive right. A competitor who reaches the same result through its own research, or by observing and analysing a product it lawfully holds, commits no wrong as a rule, unless bound by a contractual undertaking. It may even patent the invention, in which case the holder of the secret can rely in France only on a right based on prior personal possession, which allows it to continue its own use without being able to prevent anyone else from using the invention. Secrecy is also fragile, since a single leak or a moment of negligence is enough to lose it for good. Finally, it offers no title to show investors or partners.

In court, the claimant must establish the existence of the secret, the measures taken to protect it and the infringement it has suffered. Protection therefore depends on serious organisation: confidentiality clauses, internal policies, access logs and IT security.

Patent first, communication second

An invention cannot be both patented and kept secret for good, because the patent system exchanges exclusivity for publication. That incompatibility does not mean that everything must be disclosed. Before filing, discretion is a condition of patentability. After filing, the division between what will be patented and what will remain secret is a matter of strategy, depending on the nature of the invention, its lifespan and the business’s ability to guarantee confidentiality.