Abstract: IMS networks and methods are disclosed for securing media streams for IMS sessions. A CSCF of an IMS network receives a registration message, such as a SIP Register message, from user equipment (UE) of an IMS subscriber indicating whether the UE supports media security. The CSCF then forwards a registration message, such as a Diameter MAR, to a subscriber database that includes a header parameter also indicating that the UE supports media security. A media security system generates media security information (e.g., algorithms, keys, etc), and the subscriber database transmits a response message, such as a Diameter MAA, to the CSCF that includes a header parameter for the media security information. The CSCF transmits a response message, such as a SIP 200 OK message, to the UE that includes a header parameter for the media security information. The UE may use the media security information to secure media streams.