A SYSTEM AND A METHOD FOR PROVIDING A USER WITH AN ACCESS TO DIFFERENT SERVICES OF SERVICE PROVIDERS

The present invention refers to a system for providing a user with a respective access to different services of at least one service provider in a network considering privacy and security via one sole user-related unique digital identifier (D-ID), the system comprising 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-specific number 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 value it 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 case that the trust level of the selected pseudonym corresponds to that one required by the at least one service provider. The invention further refers to a respective method.