METHOD AND SYSTEM FOR MANAGING DECENTRALIZED DATA ACCESS PERMISSIONS THROUGH A BLOCKCHAIN

A data management blockchain and protocol for controlling access to data, in which no central trusted authority is required, is presented. The data management blockchain and protocol comprises an initial announcement of public keys by a plurality of blockchain participants, through which each blockchain participant establishes an identity. Subsequently a first of the plurality of blockchain participants publishes data encrypted with a cryptographic key on the blockchain. A second of the plurality of blockchain participants is assigned as an owner of the data by an authority. Access to the data is granted or revoked to further participants by the second of the plurality of blockchain participants through signed permission messages published on the blockchain, and a corresponding hand-over of the cryptographic key by the first of the plurality of blockchain participants, allowing access to the data. Access to further data may be revoked by changing the cryptographic key used.