A method comprising in a home network of a communication system, wherein one or more cryptographic key pairs are provisioned for utilization by one or more of a plurality of subscribers of the home network to conceal subscriber identifiers provided to one or more access points in the communication system: provisioning one or more privacy managing entity identifiers for utilization by the subscribers when providing their concealed subscriber identifiers to the communication system, receiving, at one of the one or more access points from a user equipment associated with a subscriber, a request for authentication data for one of the plurality of subscribers, the request for authentication data comprising a concealed subscriber identifier, a key identifier that identifies the cryptographic key pair used by the user equipment to conceal the subscriber identifier, and a privacy managing entity identifier, the privacy managing entity identifier identifying one of one or more privacy managing entities in the home network of the communication system configured to de-conceal the concealed subscriber identifier, utilizing said one of the one or more privacy managing entities in the home network of the communication system identified by the privacy managing entity identifier in the request for authentication data to de-conceal the concealed subscriber identifier; and obtaining, from one of a plurality of different instances of a user data repository, the authentication data for said one of the plurality of subscribers utilizing the de-concealed subscriber identifier, each of the plurality of different instances of the user data repository maintaining authentication data for a different subset of the plurality of subscribers of the home network of the communication system, wherein each of the one or more privacy managing entity identifiers identifies one privacy managing entity in the communication system that comprises one central privacy managing entity or a different privacy managing entity for one user data repository or several user data repositories and that is configured to de-conceal a given concealed subscriber identifier. provisioning one or more privacy managing entity identifiers for utilization by the subscribers when providing their concealed subscriber identifiers to the communication system, receiving, at one of the one or more access points from a user equipment associated with a subscriber, a request for authentication data for one of the plurality of subscribers, the request for authentication data comprising a concealed subscriber identifier, a key identifier that identifies the cryptographic key pair used by the user equipment to conceal the subscriber identifier, and a privacy managing entity identifier, the privacy managing entity identifier identifying one of one or more privacy managing entities in the home network of the communication system configured to de-conceal the concealed subscriber identifier, utilizing said one of the one or more privacy managing entities in the home network of the communication system identified by the privacy managing entity identifier in the request for authentication data to de-conceal the concealed subscriber identifier; and obtaining, from one of a plurality of different instances of a user data repository, the authentication data for said one of the plurality of subscribers utilizing the de-concealed subscriber identifier, each of the plurality of different instances of the user data repository maintaining authentication data for a different subset of the plurality of subscribers of the home network of the communication system, wherein each of the one or more privacy managing entity identifiers identifies one privacy managing entity in the communication system that comprises one central privacy managing entity or a different privacy managing entity for one user data repository or several user data repositories and that is configured to de-conceal a given concealed subscriber identifier.