Techniques for the secure generation of a set of encryption keys to be used for communication between a wireless terminal and an assisting base station in a dual-connectivity scenario. An example method includes generating an assisting security key for the assisting base station, based on an anchor base station key. The generated assisting security key is sent to the assisting base station, for use by the assisting base station in encrypting data traffic sent to the wireless terminal or in generating one or more additional assisting security keys for encrypting data traffic sent to the wireless terminal while the wireless terminal is dually connected to the anchor base station and the assisting base station. The anchor base station key, or a key derived from the anchor base station key, is used for encrypting data sent to the wireless terminal by the anchor base station.