Human Authorship in GenAI-Assisted Production: A Critical Analysis of the USCO 2025 Report

Debates over authorship in AI-assisted creative production gained significant attention following the 2025 report of the U.S. Copyright Office (USCO). This paper critically examines that report and analyzes the gap between the technological structure of generative AI—particularly diffusion models—and the actual workflows of creative production. The USCO interprets AI creation through a simplified “input → output” model and treats prompts as mere ideas. In practice, however, creative production typically emerges through iterative processes including generation, evaluation, modification, and recomposition. From technological, artistic-theoretical, and comparative legal perspectives, this paper argues that authorship in AI-assisted creation should not be assessed solely on the basis of a single input act, but rather on the totality of human involvement throughout the entire production workflow.