Blockchain offers an innovative mode to store information, execute transactions, perform functions, and establish a trust system. In the realm of secure transmission, there are challenges such as the confirmation of data integrity, the certification and traceability of transaction records, and the reliability of data accessed, among others. The blockchain is considered a technological breakthrough for cryptography and cybersecurity. Therefore, blockchain is an excellent solution for managing and securing data transmissions across various networks. With the research and development of blockchain technology, people recognize the importance of privacy protection on transaction data and identity in secure data transmission processes. The decentralized characteristics of blockchain systems can facilitate transactions with transparency, openness, and more active participation of users. However, during the actual transmission process, the content, volume, and the parties involved in the transmission may involve sensitive and private data. Therefore, a blockchain privacy protection program applied to secure data transmissions is needed. In this article, we propose a privacy data encryption application based on the normal blockchain. The application uses zero-knowledge proof to process the privacy of transaction data, and uses smart contracts to verify transaction activities in the program on the blockchain. At the same time, for the core parameters of zero-knowledge proof, we combine it with the attribute base of the supervision node to supervise the transaction of blockchain private data, so that the blockchain has a wider range of practical application value. This solution has a good performance on the efficiency and security of the data transmission.