Platform for Integrating Internet of Things Based Smart Healthcare System and Blockchain Network

In an internet of things (IoT) based smart healthcare system, personal health data can be produced by means of various wearable devices connected through a wireless body area network (WBAN). Since they contain sensitive information, whole collected data should be stored in a platform that guarantee both data confidentiality and integrity. In this sense, permissioned blockchain i.e. Hyperledger can be seen as an auspicious candidate for providing a secure yet scalable storage platform thanks to its data integrity and peers decentralization features. Considering that both IoT and blockchain network have different working mechanism, therefore, a software platform is required to provide an integration layer between the IoT and blockchain network. In this paper, we propose the design of IoT-to-Blockchain platform for integrating internet of things based smart healthcare system and blockchain network. The proposed system consists of five components including blcokchain-to-device interface, chain code execution interface, membership service provider (MSP), peers node and ordering node. The proposed system consists of five components including HTTP-based API gateway as device-to-blockchain interface, membership service provider (MSP), peers node and orderer. At first, the API gateway receives sensing data from IoT gateway device. Upon reception, the API gateway acting as client invokes chain code installed in each blockchain peer by emitting a transaction proposal to peers. Peers then simulate the execution and send back the endorsed data to the client i.e. API gateway. Collected endorsement from various peers are sent to orderer which then build a block containing an ordered transactions received from all clients and then broadcast that block to all peers. Each peer the performs a final verification before committing all ordered transactions on that block into its own local ledger. By using this mechanism, every peer in network can receive similar transaction orders which lead to identical ledger state changes.