A method in a communication network wherein users are authenticated based on network originated user identities is disclosed. The authentication method comprising the steps of receiving a network originated identity from a user and associating the network originated identity with at least one non-network originated identity stored in a data storage. When a non-network originated identity is received from the user, the non-network originated identity from the user is compared with the at least one non-network originated identity from the data storage. The user is authenticated if the comparison is valid.