Federal Circuit Holds Microsoft Metadata Can Corroborate Inventor Testimony of Conception

11.11.26

On October 19, 2026, the Federal Circuit affirmed the PTAB’s final written decision in Google LLC v. Valtrus Innovations Ltd., No. 2024-1945, holding the primary reference, Bushee, that Google relied upon to invalidate Valtrus’s claims was not prior art under pre-AIA 35 U.S.C. § 102(e) because Valtrus established an earlier conception date to Bushee’s filing date.

First, the Federal Circuit affirmed the Board’s finding that the original invention disclosure documents and their Microsoft Word metadata independently corroborated co-inventor Dr. Tsaparas’s testimony of an earlier conception date. While Google argued that these materials were the inventor’s “own statements and documents” as they were entirely under the inventor’s control, Federal Circuit precedent supports metadata is independent of an inventor’s own statements and documents. Therefore, the Court found that unlike unwitnessed laboratory notebooks or unwitnessed emails and drawings, Microsoft Word’s automatic generation of author and other metadata information could independently corroborate Dr. Tsaparas’s testimony. The Court thus held that substantial evidence supported the Board’s finding that the disclosure documents and their metadata supplied the requisite separate corroboration.

Second, the Federal Circuit affirmed the Board’s finding of reasonably continuous diligence during the eleven-business day critical period. The Court credited Valtrus’s evidence that during the relevant time period Dr. Tsaparas’s signed declaration had to be mailed from Ontario, Canada to the law firm’s California offices and that law firms typically need several weeks or more to finalize a patent application for filing. Accordingly, the Court also held that substantial evidence supported the Board’s determination that Valtrus demonstrated diligence from just prior to Bushee’s filing date until a constructive reduction to practice.

This case offers practical guidance for practitioners litigating priority under the pre-AIA first-to-invent regime, which remains relevant for older patents still being asserted and challenged. For patent owners, the decision highlights the value of preserving native files and their original metadata, because machine-generated data can supply the independent corroboration that an inventor’s own documents cannot. For challengers, the Court’s decision signals the more productive line of attack may be the reliability of the metadata itself than its independence. On diligence, the decision confirms that the length of a gap is not dispositive. What matters is whether the record explains the whole critical period, including the ordinary time attorneys and staff need to prepare and file an application.

Summer Basham Todd | Associate Attorney