  The growing potential of modern communications needs the use of secure means
to protect information from unauthorized access and use during transmission. In
general, encryption a message using cryptography techniques and then hidden a
message with a steganography methods provides an additional layer of
protection. Furthermore, using these combination reduces the chance of finding
the hidden message. This paper proposed a system which combines schemes of
cryptography with steganography for hiding secret messages and to add more
complexity for steganography. The proposed system secret message encoded with
chaotic stream cipher and afterwards the encoded data is hidden behind an RGB
or Gray cover image by modifying the kth least significant bits (k-LSB) of
cover image pixels. The resultant stego-image less distorters. After which can
be used by the recipient to extract that bit-plane of the image. In fact, the
schemes of encryption/decryption and embedding/ extracting in the proposed
system depends upon two shred secret keys between the sender and the receiver.
An experiment shows that using an unauthorized secret keys between the sender
and the receiver have totally different messages from the original ones which
improve the confidentiality of the images.
