Research On Publicly Verifiable Random Number Generation Method Based On Blockchain

Random numbers have extensive application scenarios.Whether random numbers are random or unpredictable is directly related to the benefits,fairness and security of random numbers.With the development of today's society,the problems caused by the opaque process of the random number generation process emerge in an endless stream.The demand for public transparency and verifiability of random numbers is gradually increasing.The present verifiable random number generation scheme generally relies on trusted third parties as notarization or computing center.A crash or cheating in a trusted third party can cause an interruption or an unfair situation in the process of generating random numbers.The distributed verifiable random number generation scheme does not employ a trusted third party,but it only satisfies the participants' verifiability and is not verifiable by all.For this purpose,in order to ensure the fairness of random number generation and improve the transparency of random number generation,a publicly verifiable random number generation method based on block chaining is proposed in this thesis.The main contents of the research are as follows:(1)Based on verifiable secret sharing,distributed key generation and zero knowledge proof,we propose a publicly verifiable random number generation method.The method allows multiple distrust participants to distributely generate verifiable random numbers,making it possible for everyone to verify the randomness and unpredictability of random number through evidences.The final verifiable random number can be calculated by anyone by the public information.The efficiency enhancement,efficiency analysis and security analysis of the protocol are carried out in this thesis.Efficiency enhancement uses Horner algorithm,fast exponent operation and batch verification algorithm to improve the computing efficiency of each phase of the protocol.The efficiency analysis shows that both the average value and worst value of the computational time complexity for each participant are O(9)).The security analysis proves the randomness,unpredictability,public verifiability and robustness of the method of generating random numbers.(2)In the publicly verifiable random number generation method,the participants produced evidence of their own correct implementation of the protocol by constructing a zero knowledge proof protocol.In order to prevent evidence from tampering or forgery,this thesis proposes the use of blockchain as a platform for the disclosure of evidence in the publicly verifiable random number generation method.The security of the evidence is protected by the nature of the blockchain centralization,public transparency,non tamperability and multi maintenance.This thesis designs and implements an publicly verifiable random number prototype system based on block chain platform Hyperledger Fabric,the function test and performance test of this system are also carried out.The performance test results show that the actual running time of the system increases linearly with the increase of the number of participants and the threshold of the system,and has practical application value.The publicly verifiable random number generation method based on block chaining is studied in this thesis,which enables participants to distribute efficiently,randomly,unpredictability,publicly verifiable true random numbers.It is suitable for the open and transparent properties of random numbers and high verifiability applications,especially in the field of electronic lottery.