Adopting the JPEG universal metadata box format for media authenticity annotations

The JPEG Universal Metadata Box Format (JUMBF) provides a uniform framework to support metadata-based extensions within the JPEG ecosystem. JUMBF provides a generic container in which domain specific metadata can be defined. On top of this container, JUMBF provides additional functionalities to facilitate linkage between metadata and image data. While JUMBF forms the foundation for JPEG specifications such as JPEG 360, JPEG Privacy & Security and JLINK, it is also intended for adoption by third parties. The Coalition for Content Provenance and Authenticity (C2PA) is designing an architecture for providing provenance to digital media, giving creators tools to express objective reality and empowering consumers to evaluate whether what they are seeing is trustworthy. The C2PA adopted JUMBF as the container format for their provenance information, initially in JPEG files, but will also be using it with video, audio and documents as well. As such, it serves as an interesting case study related to the adoption of JUMBF by a third party and use outside of the JPEG ecosystem. This paper presents how the C2PA uses the JUMBF architecture and proposes potential future enhancements to the JUMBF specification.