A novel image steganography technique based on similarity of bits pairs

Steganography is one of the most important information hiding mechanism, which can be used along with cryptography for providing adequate data security. The common Steganographic mediums used are text, image, audio and video for hiding secret information. In the case of image medium, mostly least significant bits of pixels of a cover image are used for hiding secret information. In this paper, a new technique based on pairs matching is proposed, data bits of the message to be secured are arranged in pairs and image pixel bits are also arranged pairwise. The pixel bits are represented in forms of pairs as, 7th and 6th bits makes 3rd pair, 6th and 5th bits are named as 2nd pair, while 5th and 4th bits are denoted with 1st pair and the last one 4th and 3rd pair represented as the 0th pair. The secret message bits are compared with all pairs and replace the least two significant bits with respective matched pair number. If no pair is matched, then replace the 0th pair with message bits, and replace two LSB with pair no 0. The proposed technique shows good quality of stego image, along with acceptable PSNR and also carries the high capacity of secret message. By comparing the results with existing techniques, the proposed technique shows good results.