I don’t know about this specific product but in general a digital signature is generated based on the content being signed, so any change to the content will make the signature invalid. It’s the whole point of using a signature.
Which means that there isn’t a way to edit the photo and have the cert match, and also no way to compress or change the file encoding without invalidating the cert.
I don’t know about this specific product but in general a digital signature is generated based on the content being signed, so any change to the content will make the signature invalid. It’s the whole point of using a signature.
I was too tired to investigate further last night. That is the case here, sections of data are hashed and used to create the certs:
https://c2pa.org/specifications/specifications/1.3/specs/C2PA_Specification.html#_hard_bindings
Which means that there isn’t a way to edit the photo and have the cert match, and also no way to compress or change the file encoding without invalidating the cert.