A New Robust Method of Hiding Text Characters for Secure Open Channel Transmission

This paper discusses a new method of hiding ASCII characters based on match between bit value of the randomly selected image pixel and the data bits. Bit positions in the higher nibbles of the cover image are used for data hiding at a position indicated using a 2-bit code. Simulation results on Lena, Gibbon and Cat images [1] for hiding a large set of ASCII text characters indicate that suggested technique achieves PSNR up to 44.7 dB as against minimum required 34 dB for acceptable perceptual quality [2]. Also, the bounds of the change in the original pixel value due to data hiding are limited to ± 3. Therefore besides retaining perceptual quality of the original cover the proposed method offers high robustness as compared to the LSB insertion technique [3, 4], it is less prone to attacks by eaves droppers and hence it can be effectively used for secure open channel transmissions.