vGuard: A Spatiotemporal Efficiency Supervision Method For Vaccine Production Based On Doublelevel Blockchain A vaccine is a biological production that is related to peopleu0027s lives. Currently, vaccine production supervision is very rough. The vaccine production records are completely controlled by the enterprise. Enterprises only submit production records to review agency for review when they need to sell vaccines. Production records are easy to forge and modify. In order to solve the shortcomings of traditional centralized management. We propose a supervision method for vaccine production based on doublelevel blockchain. We have designed a doublelevel blockchain structure. The first level is private data of vaccine production enterprise, including production records and corresponding hash. The next level is public data, including production records hash and vaccine information. In this way, we make vaccine enterprise to submit production records in a timely manner without fear of privacy leaks. We avoid enterprise tampering or falsification of production records through the nontampering features and time stamps of the blockchain. Through these methods, we have realized efficiency supervision of vaccine production.

CustomsBased Blockchain Solution for Exportation Protection. As part of the international trade supply chain, Dubai Customs acts as the gatekeeper, protecting the society and the economy. During the exportation process, one of the primary responsibilities of the Customs Authority is to authenticate the documents submitted with the exportation declaration application, to ensure the legality of the trade. Due to the lack of direct communication channel among the exportation supply chain participants, authenticating the exportation application documents is a timeconsuming and challenging task. Typically, there is no direct communication paradigm among the supply chain participants. Therefore, in most cases, the authenticating process relies on human judgment. This increases the chance of nondetection of fraudulent exportation documents. In this regard, the redesign of the exportation supply chain to automate the authentication process has become an essential requirement. This paper addresses this requirement by proposing a blockchainbased system, which establishes a direct, tamperproof information exchange mechanism among the participants. We target the car exportation supply chain; however, with slight modification, the proposed system can be easily applied to any other exportation supply chain too. To validate the performance of the proposed system, we implement a ProofofConcept (POC) using the IBM Hyperledger fabric.