Abstract
This paper proposes a global blockchain-based vaccination certification. To facilitate issuing and verifying certificates globally, the framework is lightweight on the user's side. The essential certification operations, issuing certificate, verifying certificate, and verifying vaccine, are implemented preserving user's privacy. Our framework's smart contracts design is implemented on the Ethereum blockchain test network to support indexing and querying the certification data. The experimental results show the effectiveness of the proposed approach in improving the performance of the primary functionalities. The results show the retrieving time of certificate information is efficient no matter how long the chain is, compared with scanning the blocks to find the target data.