The invention relates to a method for providing an identity-related information (IRI) to a requesting entity (50) by means of an identity provider (40). The invention comprises: a first authenticity reference part generation step (IVa), comprising the generation of a first authenticity reference part (art 1) by the identity provider (40); a first authenticity reference communication step (IVb, IVd) between the client application (30) and the identity provider (40) comprising the communication of the first authenticity reference part (art 1); a second authenticity reference part generation step (VI), comprising the generation of a second authenticity reference part (art 2) by the identity provider (40); a second authenticity reference communication step (VIII, IX) between the identity provider (40) and the requesting entity (50) by means of the first communication protocol comprising the communication of the second authenticity reference part (art 2) and in the referrer element the communication of the first authenticity reference part (art 1).