Protecting personal sensitive data security in the cloud with blockchain

To protect personal sensitive data in cloud computing environment, certain issues need to be addressed, including data ownership, fine-grained access control, transparency and auditability. While many models have been explored to address these issues, among most of which, some components, such as Cloud Service Provider (CSP) are required to be trusted. In this chapter, we introduce a trust-free data access model for personal sensitive data protection in the cloud environment. In our model, an access control mechanism is constructed based on the Ethereum blockchain, which requires no trusted party. The smart contract enables fine-grained access control for cloud data based on the blockchain. Data operations including uploading, updating and downloading can be automated processed and logged in our model to ensure transparency and auditability. Comparisons between our model and existing models show that our trust-free model fulfills all requirements on personal sensitive data protection, and brings no extra security risks. Moreover, our model has less burden for data owner from both the computation perspective and communication perspective.