Data2.cash is a user data assets trading protocol that allows individuals to aggregate web2 and web3 data, creating anonymous profiles on the blockchain using zero-knowledge proofs, and selling the rights to use their data while maintaining privacy. Data2.cash supports multiple uses of user data, with the first application being a precise marketing platform. Web3 projects can select desired tags and send specific promotions to users via email/Telegram, etc. Users receive cashback for providing their data when they receive Components Personal Data Vault(PDV): Users can import their web2 and web3 accounts into a personal data vault, generate zero-knowledge proof tags, and link these tags to a public account. Users can create an anonymous profile through their PDV. They can control their data, choose which tags to show or hide, and see the earnings from each use of their data. Data Exchange: The data exchange allows developers to pay for queries of on-chain anonymous user profiles, in a fully permissionless way. The authenticity of these tags is guaranteed by zero-knowledge proofs. End-to-End Channel: Each anonymous profile has an end-to-end channel with its owner, meaning messages sent to the anonymous profile directly reach the owner. Precise Advertising Platform: Connected to the data exchange, companies can customize tags for their target users in the advertiser center, find users with these tags, and distribute exclusive offers through the end-to-end channel.