"Security comes in first place when sending confidential digital data over an insecure transmission medium. As the data can be easily tampered with, having a single layer of security is not sufficient. In this paper, a four level security scheme is proposed associating with the idea of digital watermarking, steganography, cryptography and covert channel. The data to be transmitted is first hidden inside a cover image and then watermarked for ensuring authentication and validating data integrity. Further, encryption is applied on the watermarked image to achieve second level of data integrity and finally the data is transmitted in a hidden manner through an appropriate covert channel."