According to an example aspect of the present invention, there is provided an apparatus configured at least to determine whether a cryptographic signature of a token received in the apparatus from a network function consumer is valid, obtain a cryptographic signature of the apparatus of the token responsive to the cryptographic signature of the token being valid, and provide the token to a peer entity of the apparatus, wherein the cryptographic signature of the apparatus is either included into the token or provided in a header external to the token, wherein the peer entity is comprised in a second network, different from a first network where the apparatus is comprised in. The request may serve a user equipment, directly or indirectly.