###### Abstract  
The non-fungible tokens trading of digital content works, as an emerging business model, has rapidly developed while also posing challenges to current copyright protection. The NFT infringement incidents in recent years have exposed many issues, such as lack of government regulation, imperfect copyright protection mechanisms, and illegal profits from service platforms. Considering the collusive behavior during the NFT printing process, this study uses evolutionary game theory to model a game composed of three populations: digital content creators; NFT service platforms; and government regulatory agencies. We derived and analyzed the replication dynamics of the game to determine the evolutionary stability strategy. In addition, combined with numerical simulations, we also analyzed the impact of individual factors on the stability of system evolution. This study identifies that the incentives and fines set by the government must be above a certain threshold in order for game results to develop toward an ideal equilibrium state, and the government can try to improve the efficiency of obtaining and updating market information and set dynamic punishment and reward mechanisms based on this. This study also found that excessive rewards are not conducive to the government fulfilling its own regulatory responsibilities. In this regard, the government can use information technology to reduce the cost of regulation, thereby partially offsetting the costs brought about by incentive mechanisms. In addition, the government can also enhance the governance participation of platforms and creators to improve the robustness of digital copyright protection by strengthening media construction and cultivating public copyright awareness. This study helps to understand the complex relationship between NFT service platforms, digital content creators, and government regulatory authorities and proves the practical meaning of countermeasures and suggestions for improving government digital copyright regulations. NFT digital works; copyright protection; collusive behavior; evolutionary games; simulation analysis +
Footnote †: journal: Applied Sciences  
traded NFTs in 2021, and this number was only 0.089 million in the previous year; the number of buyers has also increased from 0.075 million in 2020 to 2.3 million. In addition, in 2021, investors earned about $5.4 billion in profits from NFT sales, with about 470 wallets earning more than $1 million in profits [4]. These data not only reflect the commercial value of NFT digital publishing, but also confirm that NFT digital publishing is ushering in a new era globally. With the application of NFT, its inherent limitations are gradually becoming apparent. In recent years, NFT infringement cases have been constantly emerging. In February 2023, the case of the famous French luxury brand Hermes against the artist [PERSON] came to an end [5]. The jury ruled that the \"MetaBirkins\" NFTs series designed by [PERSON] had the potential to confuse consumers and was suspected of trademark infringement, trademark dilution, and domain name squatting. Industry pioneer Dapper Labs (the development company of CryptoKitties, Vancouver, BC, Canada) has also been involved in infringement incidents. In 2017, a virtual cat in CryptoKitties caused a copyright dispute by taking images from copyrighted artwork without the permission of the original copyright holder [6]. OpenSea, the world's largest NFT service platform, claims that more than 80% of the assets created by their simplified \"lazy casting\" process are plagiarized works, fake collections, and spam [7]. NFT has not yet truly fulfilled its promise to protect digital rights. On the one hand, there are still shortcomings in the application of NFT technology in digital publishing. The original intention of NFT's application in the digital publishing industry was to use its unique digital ownership certificate to assist in the authentication of digital works [8].