Research And Design Of Immunity Passport Scheme Based On Blockchain

The outbreak of COVID-19 is an unprecedented predicament for human society.It is spreading and worsening rapidly in many countries and regions around the world,posing a serious threat to people’s lives and health,and affecting the order of production and life in all countries.How to restore and develop the economy,ease people’s living pressure,and resume normal production and life and international exchanges is an important issue facing the current situation.Vaccination is one of the effective measures to prevent the novel coronavirus.A number of countries and organizations have successively introduced immunity passports,which allow people to work and travel abroad without harming personal or public health.However,due to differences in policies,technical standards and religious beliefs,the validity and reliability of immunity passports remain controversial among different countries,increasing the difficulty of unified management.In addition,the issue of counterfeit immunity passports and the privacy of vaccination users have also plagued the implementation of the program.Aiming at the above problems,the research focuses of this thesis are as follows:(1)In order to adapt to the international travel scenario,this thesis proposes an immunity passport scheme based on the dual-blockchain architecture for international travel.A dual-blockchain architecture is designed,which includes two different types of domestic and international blockchains.Searchable encryption and anonymous authentication are used to ensure users’ privacy,so that users could control their own data.Users are allowed to use legitimate pseudonyms to participate in vaccination,certification,and other processes to address the stigma of vaccination.Moreover,the performance and security evaluation show that the proposed scheme achieves the proposed security goals and surpasses other authentication schemes in terms of communication and computation overhead.(2)Aiming at the security,privacy and efficiency of entry and exit credentials and their contents in the case of multiple users(user groups),an immunity passport storage,sharing and verification scheme for multi-user is proposed,which is improved on the basis of the immunity passport scheme based on the dual-blockchain architecture for international travel.The immunity passport data is stored by on-chain and off-chain collaborative storage,which realizes data confidentiality,traceability and non-repudiation.The searchable encryption technology and blockchain technology are combined to realize the secure sharing of immunity passports.For multi-user scenarios,the improved aggregate signature technology realizes fast traceability of malicious forgers and reduces the computational overhead of the scheme.Security analysis shows that the proposed scheme satisfies data confidentiality,traceability,non-repudiation and unforgeability.Performance analysis shows that the proposed scheme has certain advantages in terms of computation and communication overhead.