The Shadow Lurking in the Z6 III: What is the 'Backdoor' Issue in Nikon's C2PA Authentication? | Release #594

The C2PA feature, designed to ensure photo authenticity and prevent tampering, has been anticipated as a cornerstone of a trustworthy visual media era.

However, reports from creator forums have revealed that the C2PA feature implemented in the has a vulnerability that allows 'authenticity' to be faked. Nikon is currently investigating, and this issue is not just a rumor but a real security concern.

The core of this vulnerability lies in the 'multiple exposure' feature of the . While originally intended for creative expression, this feature allows users to overlay non-C2PA-compliant images or AI-generated images, enabling them to be authenticated as 'genuine photos' with C2PA signatures.

Although the cryptographic technology itself has not been breached, the vulnerability exploits weaknesses in the implementation.

has already begun investigations and is considering fixes in future firmware updates. Possible measures include preventing the use of non-C2PA-signed images as materials for multiple exposure or disabling signatures within this feature altogether.

Until then, it is advisable to avoid placing absolute trust in C2PA-signed images generated by the .