IP based communications are becoming more and more ubiquitous and hence the need for reliable and faster algorithms that can provide authentication, confidentiality and integrity. However, not much attention is paid to large volume data communications such as VoIP, IPTV, IP Multimedia Subsystems (IMS), etc. Large volume data communications require simple, easy to implement and extremely fast algorithms and protocols for encryption and decryption. It is also important to establish mathematically the robustness of algorithms and protocols to prove their validity, reliability and usefulness for high-end applications. In this paper we describe an easy to implement, single-key encryption algorithm and a protocol that demonstrates the security of the scheme for IP based communications such as VoIP, IPTV, IMS, and for large volume data communication over the Internet. This scheme can be implemented as bump-in-the-code or bump-in-the-wire.