Multimedia conferences held using services provided by clouds owned by third party companies are becoming increasingly popular. While using such services, end users will want to keep their audio/video data private when they pass through the servers situated in the cloud. Application of SRTP (Secure Real-time Transport Protocol) in such use cases fail to provide the desired privacy because it leads to sharing the master keys for encryption and authentication of the media content with the semi trusted media servers of the cloud. As a solution, modifications of SRTP are proposed in this thesis with the result of redesigning the security mechanisms of RTP header extensions and RTCP packets by separating the cryptographic contexts and keying materials for protecting end-to-end sensitive data. A couple of design choices for key management through DTLS-SRTP for Cloud conferencingare also proposed. Moreover, analysis of existing solutions for modifying SRTP packets for cloud conferences have also been carried out in this project. The solutions are found by studying related protocols, understating the problems and analyzing current solutions if there were any. The proposed solutions show different alternatives to solve a specific problem and their tradeoffs in terms of complexity and compatibility with current standards.