The invention relates to a computer implemented method for analyzing data of a first user, wherein an asymmetric cryptographic key pair is associated with the first user, said asymmetric cryptographic key pair comprising a public key and a private key, the data being stored pseudonymously in a database with the data being assigned to an identifier, wherein the identifier comprises the public key, the method comprising: receiving a set of rules, the set of rules describing data processing steps, receiving the identifier, retrieving the data assigned to the identifier from the database, analyzing the retrieved data by applying the set of rules, providing a result of the analysis.