There is disclosed a method in a communications system for enabling authentication of a sender device and a receiver device in the communication system, wherein the sender device is associated with a self-generated first identity and a first master device, the receiver device is associated with a self-generated second identity and a second master device and wherein the authentication is enabled by utilizing the first master device and the second master device for the sender device and the receiver device to verify the identities of each other. In one embodiment, both the sender device and the receiver device are also associated with a third device ant the third device is used in addition to the master devices for verifying said identities. There is also disclosed a method In a sender device, a method in a receiver device, a method in a third device, a sender device, a receiver device, a third device, and a computer program product for the same.