Microsoft AI watermarks in Paint and Photos are linked to user IDs, researcher finds
- ID
- 17504
- Status
- summarized
- Published
- 25 Aug 2026, 8:10 AM
- Fetched
- 25 Aug 2026, 10:21 AM
- Provider
- The Register
- Category
- technology
- Original URL
- https://www.theregister.com/ai-and-ml/2026/08/25/microsoft-ai-watermarks-in-paint-and-photos-are-linked-to-user-ids-researcher-finds/5292034
- Source URL
- https://www.theregister.com/headlines.atom
Summary
- Score
- 5.5
- Created
- 25 Aug 2026, 10:22 AM
- Tags
- Audience
- developersai-ml-learners
What happened
Researcher Xusheng Li at Vector 35 found that Microsoft Paint and Photos embed a server-issued 16-byte GUID as an invisible watermark in AI-generated images, distinct from the visible watermark option. The user's prompt is sent to Microsoft for moderation, and the returned GUID is encoded into the pixels, potentially linking the image back to the user who created it. Microsoft disclosed this in documentation but did not detail the mechanism until Li's analysis.
Why it matters
If you use Microsoft Paint or Photos AI features to generate images you intend to publish or share, each output carries an invisible identifier tied to your prompt and potentially your account. Builders integrating AI image generation into products should understand that 'local' generation via hosted services can leak provenance metadata, and EU AI transparency rules (190+ signatories) will push more providers toward similar watermarking.
Discussion angle
How much provenance metadata should AI-generated content carry, and does invisible user-linked watermarking cross from transparency into surveillance—especially when the prompt itself is sent to a server for moderation?