Digital Content Authenticity and Transparency Act established; civil penalty. Requires a developer of an artificial intelligence system or service to apply provenance data to synthetic digital content that is generated by such developer's generative artificial intelligence system or service and requires a developer to make a provenance application tool and a provenance reader available to the public. The bill requires a controller of an online service, product, or feature to retain any available provenance data and requires a capture device to include a provenance application tool by default. The bill grants the Attorney General the exclusive authority to enforce such provisions and impose civil penalties pursuant to the bill. Under certain circumstances, the Attorney General may offer a developer an opportunity to cure a violation before imposing such civil penalties. The bill has a delayed effective date of July 1, 2026.