Abstract: With the development and progress of society,many application scenarios require voting.The current electronic voting system has the characteristics of centralization,the voting process is difficult to be open and transparent,voters cannot verify the results of the ballot,and a trusted third-party vote-counting agency is required to participate in the voting.In response to the above problems,in order to better adapt to the increasingly abundant application scenarios,this paper studies and proposes a distributed encrypted voting system based on blockchain.The ElGamal encryption algorithm in a distributed environment ensures the security and confidentiality of the entire voting process,and no one or organization can crack the intermediate results of obtaining votes.The automatic execution mechanism of blockchain smart contract replaces the traditional third-party trusted ticket counting agency to realize automatic ticket counting.Since all voting information is stored on blockchain,it further ensures that the voting process is transparent and open,and the results can be verified and traceable.Experimental verification shows that the bottleneck of the voting system is the accumulative multiplication algorithm in the voting process.In order to improve computing efficiency,the method of on-chain and off-chain collaborative computing is further adopted.Under the premise of ensuring the security of bills,the off-chain speed of calculation is accelerated through parallel computing.Finally,the security and performance analysis shows that the mechanism has good scalability and is a practical and safe electronic voting system design scheme.

Key words: Electronic voting, Blockchain, Smart contract, ElGamal algorithm, Collaborative computing