<span lang="en">IP Multimedia Subsystem (IMS) is becoming the prevailing candidate for managing future mobile multimedia communications, including critical communications such as public safety, emergency professionals and corporate networks. IMS security and privacy has gained much attention in the few last years. The review of recent IMS security activities stresses the inclusion of intermediate nodes in the media path of secured communications as an open issue. This paper presents an end-to-middle-to-end solution which enables the usage of IMS media plane elements such as recorders, transcoders and novel cross-ciphering functions in a secure way. The proposed solution, which is fully compliant with IMS, includes the network architecture, the signaling plane for session signaling and key management, and the media-plane security characteristics. Experimental results demonstrate that the proposed solution can provide media interoperability (both transcoding and cross-ciphering) with a cost of 17% overhead to a standard IMS call setup in the signaling plane.</span>