The petitioner challenged a patent in an inter partes review where the patent claimed a method and apparatus that generates content-based identifiers for data items to resolve problems arising from traditional naming protocols in conventional data processing systems. In its final written decision, the Patent Trial and Appeal Board (PTAB) found the claims obvious. To reach this conclusion, the PTAB agreed with the petitioner’s argument that the prior art “necessarily must” perform in the manner required by the claims. This was interpreted by the Federal Circuit as a finding of inherency.

The patent owner appealed, and the Federal Circuit reversed. The court concluded that the PTAB’s final written decision lacked substantial evidence. The court explained that while it was possible that the prior art system utilized the claim limitation at issue as argued by the petitioner, the patentee suggested an equally plausible understanding of the prior art, supported by disclosures in the reference, that would not utilize the limitation at issue. The Federal Circuit explained that inherency must necessarily exist in the prior art and “a mere possibility is not enough.” Because the disputed claim limitation did not undeniably exist in the prior art, the PTAB improperly relied on inherency in its obviousness analysis.

A copy of the opinion can be found here