PSP (Private Social Platform, private chain) is committed to creating a differentiated social platform, dedicated to achieving high-privacy social interaction, meeting the needs of the new generation of Internet users, and making up for the lack of social platforms such as WeChat and Weibo. PSP is implemented based on the Ethereum public blockchain system. All users with an Ethereum address can freely join the platform and conduct social activities, thus ensuring a hot start of the system. PSP integrates common social functions, such as chat, group chat, circle of friends and so on. Users can choose a private social mode when performing any social operations, so that relevant information will go through the Ethereum network for encrypted transmission.