The largest patent dispute to date at the Unified Patent Court (UPC) kicked off in Paris this week, pitting patent holder KeeeX against tech giants Adobe and OpenAI, along with other digital content verification groups. The case centers on EP 2 949 070, a patent KeeeX claims covers a method for verifying the integrity and authenticity of digital data blocks—a process central to tools used by Adobe, OpenAI, and others to check or process content.

After numerous skirmishes over procedural questions and one of the highest demands of damages to date, this morning the case on the merits between patent holder KeeeX and several defendants, among them Adobe and OpenAI, kicked off at the UPC’s local division Paris.

The defendants have countered with requests to revoke the patent, arguing that its claims are either too broad or already anticipated by existing standards. The counterclaims are identified under the case numbers UPC_CFI_530/2025, UPC-CFI-0000003/2026, UPC-CFI-0002285/2025, UPC-CFI-0002281/2025 and UPC-CFI-0002274/2025.

At the heart of the technical dispute is claim 1 of the patent, particularly the term “digital identification fingerprint.” KeeeX argues this refers to a specific, narrow method distinct from digital signatures, while the defendants push for a broader interpretation. The parties also clash over what constitutes a “digital data block”, how the fingerprint is calculated, and how linked blocks are verified.

The defendants cite prior art, including KANAI, OpenPGP, and the PDF standard, to challenge the patent’s validity. KeeeX, for its part, has submitted amended claim sets as alternatives, though the court has not yet ruled on their merits. An order dated 22 September 2026 expressly states that the interpretation of claim 1 and the related validity issues are to be resolved on the merits.

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Damages claims and procedural hurdles escalate

The case has already generated unusual procedural fireworks. KeeeX initially demanded €5.6 billion in material damages and €1 billion in non-material damages-one of the highest claims ever filed at the UPC. In the current proceedings, the patent holder instead seeks €100 million plus €20 million in interim damages. The Paris division allowed this claim to proceed as a procedural matter, in summer the Court of Appeal rejected Adobe’s request for discretionary review.

This focus stems from a separate order issued in June 2026, which specifically addressed the question of interim damages and set the procedural framework for assessing the €100 million claim.

Jurisdictional disputes have further complicated the case. Last November, the Paris division initially rejected objections to its authority, but an appeal partially overturned this, stripping the UPC of power to rule on infringement claims tied to the patent’s Swiss, Spanish, British, Irish, Norwegian, and Polish designations. Meanwhile, security for legal costs became a battleground: KeeeX was ordered to post €200,000, later increased to €300,000, after Adobe’s attempt to secure a default judgment failed due to procedural technicalities. In July, the Paris local division increased the security by €100,000, bringing it to €300,000 in total. The division affirmed these procedural rulings on 29 July, confirming the refusal to admit the late amendment and the exclusion of the two additional product claims.

Adobe’s parallel push to invalidate patent

Beyond the UPC, Adobe has separately launched a nullity action at Germany’s Federal Patent Court (case ID: 6 Ni 61/25), seeking to invalidate the patent entirely. This parallel track adds another layer to the dispute, with Adobe’s legal team drawing on experience from both French and German patent litigation.

The hearing in Paris this week will focus on the core technical and legal questions left unresolved by earlier rulings. With most parties relying on French-based legal teams, including Fidal for KeeeX, Duclos, Thorne, Mollet-Viéville and Powell Gilbert for Adobe, and Clifford Chance for OpenAI, the case reflects the growing importance of the UPC as a forum for high-stakes patent disputes in the digital content space.