The emerging blockchain technology has enabledvarious decentralised applications in a trustless environmentwithout relying on a trusted intermediary. It is expected as apromising solution to tackle sophisticated challenges on personaldata management, thanks to its advanced features such as im-mutability, decentralisation and transparency. Although certainapproaches have been proposed to address technical difficultiesin personal data management; most of them only provided pre-liminary methodological exploration. Alarmingly, when utilisingBlockchain for developing a personal data management system,fictions have occurred in existing approaches and been promul-gated in the literature. Such fictions are theoretically doable;however, by thoroughly breaking down consensus protocols andtransaction validation processes, we clarify that such existingapproaches are either impractical or highly inefficient due tothe natural limitations of the blockchain and Smart Contractstechnologies. This encourages us to propose a feasible solution inwhich such fictions are reduced by designing a novel systemarchitecture with a blockchain-based “proof of permission”protocol. We demonstrate the feasibility and efficiency of theproposed models by implementing a clinical data sharing servicebuilt on top of a public blockchain platform. We believe thatour research resolves existing ambiguity and take a step furtheron providing a practically feasible solution for decentralisedpersonal data management.