Security in communications especially in group communication plays a major role in today’s world and it has to be implemented properly with the help of an efficient and robust encryption and decryption methodology. In a Multicast communication the media used is wireless and it is difficult to communicate the message secure and secretly to the group members in the normal form of message, thus we go in search of an efficient cryptographic scheme for encrypting that plain text into a cipher text. In this paper, we propose a cryptographic scheme based on RSA and the primer concept used in PCR technology. The proposed scheme yields better result than the existing schemes. © RJPT All rights reserved.