Methods, User Equipment (UE), and source network node for resuming a Radio Resource Control (RRC) connection to a target cell in a wireless communications network. The UE generates a security token using a set of input parameters and sends a resuming request with the security token to a target network node serving the target cell. When receiving the resuming request, the source network node generates a security token using a set of input parameters in the same manner as the UE. If the received security token is successfully verified when compared with the generated security token, the source network node provides to the target network node a UE context of the UE, to enable the target network node to resume the RRC connection.