There is provided mechanisms for authenticating a first radio communication device with a network. A method is performed by the first radio communication device. The method comprises obtaining credentials for a network subscription to the network. The method comprises obtaining an upper part of a radio protocol stack, according to which radio protocol stack the first radio communication device is configured to communicate with the network. The method comprises authenticating with the network. The method comprises providing, to a second radio communication device, at least one key, as derived from the credentials during the authenticating, for use by the second radio communication device when executing the remaining part of the radio protocol stack for communication between the second radio communication device and the network.