C2PA only works if everything is signed

The European Union AI Act is Europe’s attempt to comprehensively regulate AI usage. A big part of that is the requirement that AI-generated content be identifiable: either tagged with a watermark or with what the Act calls “digitally signed metadata”1. Since all this becomes enforceable in a month, it’s worth figuring out if it makes any sense. I recently discussed AI watermarking at length in Text AI watermarks will always be trivial to remove. What about digitally signed metadata? The most well-known implementation of digitally signed metadata is C2PA Content Credentials, which incorrectly2 claims to be the technology that the AI Act gives as an example of how to do signed metadata properly. The idea here is that every single image file should contain unspoofable authorship metadata. Here’s my position on it: C2PA broadly makes sense and is a good idea It is pointless to use C2PA for AI-generated images only It will take many years for C2PA to be adopted across all images Because…