Fecha de publicación: 19/08/2021 Fuente: Wipo "digitalization" Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for controlling authorization of access to user data. One of the methods includes receiving a first request that includes a first digital activity decentralized identifier (DID) and a first hash value of first digital activity data; storing the first digital activity decentralized identifier and the first hash value in a first record in a decentralized identifier blockchain that is configured to store records associated with a plurality of decentralized identifiers of a plurality of users; and controlling authorization of access to the first digital activity data stored in the first consortium blockchain using information stored in the first record in the decentralized identifier blockchain, including determining whether to authorize another user access to the first digital activity data based on the information stored in the first record in the decentralized identifier blockchain.