SDGchain: When Service Dependency Graph Meets Blockchain to Enhance Privacy

Nowadays, the number of services is increasing which allows users to perform their tasks easily. A huge amount of data is published regularly where the personal data takes the lion's share. In fact, personal data protection remains a big issue as far as how the service provider collected the data and for what purpose. Therefore, the privacy of the data owner has to be preserved by putting a strategy to control the data usage by the services. The concept of inter services privacy has been marginalized in the previous privacy preserving works. This paper proposes SDGchain, a secure and privacy-preserving decentralized model that uses secure service dependency graph (SDG) combined with permissioned blockchain Hyperledger fabric, which cooperates with an off-chain storage. In our design the SDG is used to control inter services interactions by building dependencies, measuring the level of trust, calculating the quality of service to ensure the privacy preservation of the service using blockchain to support authentication, access control and the logging operations for immutable and auditable history.