Privacy protection is of extreme importance especially in security sensitive environments. Neither cryptography nor steganography comes up with ultimate solution for privacy preservation in open systems. However, combination of steganography and cryptography can greatly increase the security of communication and is usually considered a good practice for securing security driven communication environments. In this paper we propose a novel scheme for image authentication and secret data sharing based on three level security model viz: Compression, steganography and cryptography. Compression optimizes the resource usage, steganography conceals the existence of message and cryptography is used to achieve confidentiality and authentication.