There is provided a computer-implemented method for a first party to control permission for access to first party information to a second party while preserving privacy, the method comprising the following steps taken by the first party at first party computing apparatus: establishing with the second party a set of information classes for first party information to be provided to the second party and establishing permitted use for the first party information in the set of information classes; providing a first party consent to the permitted use for the first party information in the set of information classes, encrypting the first party consent for inspection limited to the first party and the second party, and providing the first party consent to the second party in a first party digitally signed consent grant structure for the second party to decrypt, validate and sign the first party consent and for a consent validating party to store the first and second party digitally signed consent grant structure on a blockchain. There is also provided a computer-implemented method for a second party to obtain permission from a first party for access to first party information while preserving privacy. There is also provided a computer-implemented method for a consent validating party to manage permissions given by a first party for access to first party information to a second party while preserving privacy.