A RAN node (2) receives a message containing a Non-Access Stratum (NAS) security parameter from a radio terminal (1), during a procedure in which the radio terminal (1) requests the RAN node to broadcast on-demand system information. The RAN node (2) sends an authentication request message containing the NAS security parameter to a core network node (3), in order to request authentication of the radio terminal (1). The RAN node (2) broadcasts the on-demand system information in response to receiving from the core network node (3) an authentication response message indicating successful authentication of the radio terminal (1). This can contribute to, for example, preventing on-demand SI from being broadcast in response to a request from a malicious radio terminal.