Can an encrypted publication be prior art?

Question

If a description of an invention is published in an encrypted form, can it still count as prior art?

(If the encryption key is later released).

Answer 1

If a description of an invention is published in an encrypted form, can it still count as prior art?

No.

Well, probably. I couldn't find any case law on this point exactly (which, perhaps, is not so surprising). However, I feel reasonably confident that the answer is no. However, the answer below includes a lot of “I think”s, and therefore should be taken more as a weakly-supported thesis than a statement of fact.

There is a long chain of cases which consider how prior art should be interpreted, particularly in view of the enablement requirement. In a more recent one, Impax Laboratories Inc v Aventis Pharmaceuticals Inc, 545 F.3d 1312, 1314 (Fed. Cir. 2008)), the Court held:

In order to anticipate a claimed invention, a prior art reference must enable one of ordinary skill in the art to make the invention without undue experimentation. … The "undue experimentation" component of that equation examines (1) the quantity of experimentation; (2) the amount of direction or guidance present; (3) the presence or absence of working examples; (4) the nature of the invention; (5) the state of the prior art; (6) the relative skill of those in the art; (7) the predictability or unpredictability of the art; and (8) the breadth of the claims.

Undue experimentation conventionally refers to how much the skilled person needs to do to make the disclosure enabling through further research. But it would likely apply by analogy to the steps needed to take to make the disclosure enabling through making the disclosure accessible.

Thus, the question becomes: does the encrypted prior art enable the skilled person to make the invention without undue experimentation?

I think the answer to that is quite clearly no. If the skilled person is not aware of the encryption key, there is no practical way of decrypting the encrypted information. Any kind of brute forcing the key would surely be analogous to having to having to randomly perform experiments and make modifications hoping to find the claimed invention. Such a step is certainly undue experimentation.

Because of this, the encrypted prior art cannot be held to anticipate a claimed invention.

What about if the key is released?

In that case, I think the answer may be yes, though it would likely depend on how the key is released.

If it was clearly tied to the encrypted file, along with details of the algorithm used for encryption, there would be a good argument (I think) that the skilled person could straightforwardly decrypt it without undue experimentation (or indeed, without any experimentation really, given there are clear instructions). The date of the prior art would be the release of the key in that case, as that would be the date that the prior art became enabling.

In contrast, if the key was simply put on a website, but not linked to the encrypted file specifically, it seems likely that this would not really cure the inaccessibility of the encrypted prior art. It would still require undue experimentation to find the key and work out how to use it to decrypt.