Abstract: This paper introduces a distributed contract-based electricity transfer system leveraging blockchain technology to adapt to the diversity of the electricity market and the volatility in electricity demand. The necessary contracts for electricity transfer， namely， original contracts， electricity mutual assurance agreements， and transfer transaction contracts， are categorized into three distinct types. Specific protocols are designed for the generation of each type of contract. Verification of contract authenticity is performed using ordered multi-signature schemes， ensuring the validity of the contracts. Furthermore， broadcast encryption is employed to safeguard the privacy and accuracy of contract content. All contracts are stored on the blockchain， guaranteeing their immutability. The results of experiments demonstrate that this system significantly enhances the efficiency of contract generation and verification， facilitating swift and secure electricity transfers.

Key words: blockchain, sequential multi-signature, broadcast encryption, contractual electricity transfer, electricity demand