In the last few months, there has been a huge hype for the Metaverse, the 3D virtual space in which the users, through their avatars, can interact with other people and software applications. The rapid progress of multimedia technologies like Virtual and Augmented Reality has certainly has speeded up the development of the Metaverse. At the same time, this virtual world will for sure benefit from the technical advances of blockchain, which will allow building a fair, free and sustainable virtual society. In this paper, the researchers of the Chinese University of Hong Kong propose a blockchain-based three-layer architecture for…