System And Method For Providing User With Access To Different Services Of Service Providers

The present invention refers to a system and a method for providing a user with an access to different services of service providers. The system comprises at least a D-ID middleware (620) and a D-ID-agent (610), wherein, whenever the user intends to access one desired service of the different services, the user selects one pseudonym and the D-ID agent (610) reveals a secret of a pseudonym-specificnumber of secrets and a corresponding authentication path as derived from a pseudonym-specific Merkle-tree (650) to the service provider, the service provider forwards the pseudonym to the D-ID middleware (620) in order to receive a corresponding root value and trust level, and computes based on the secret and the authentication path a root value and verifies if it is matching with the root valueit has received from the D-ID middleware (620) for the pseudonym, thus verifying that the user is the owner of the pseudonym and if yes, allowing to the user access to the desired service in the casethat the trust level of th