The X Cube, also known as the Super Magic Cube, aims to establish a platform that offers secure storage and transfer of players assets. Asset transactions are mandatorily conducted simultaneously, thus enabling a trustworthy trading platform without the need for intermediaries. Additionally, this platform stores the assets of gamers, which are originally kept in the internal DB of game services, in an external DB outside of the game service, i.e., on the blockchain, to facilitate the mutual transfer of assets between games.