Steganography is the problem of hiding secret messages in “innocent-looking” public communication so that the presence of the secret messages cannot be detected
 
This project focuses on the dual problem of steganography, How can two communicating entities send secret messages over a public or audited channel so that a third party cannot detect the presence of the secret messages .The goal of steganography is different from classical encryption, which seeks to conceal the content of secret messages: Steganography is about hiding the very existence of the secret message
 
This project use cryptographic and complexity-theoretic proof techniques to show that the existence of one-way functions and the ability to sample from the channel are necessary conditions for secure steganography. This project then construct a steganographic protocol, based on rejection sampling from the channel, that is provably secure and has nearly optimal bandwidth under these conditions.