Study of the MSB information-hiding technique in a carrier image
Ren Zhi · Optics and Precision Engineering · 2002
Encryption technique is an important method to ensure safe communication, but it has a shortcoming. Because the files encrypted are vulnerable to attackers, they may be destroyed.To solve the problem, the authors take advantages of the encryption technique and information_hiding technique, i.e. concealing the information encrypted into a carrier file. The authors adopts color image files being used in the Internet. If human eyes can not observe the diversifications of the carrier image before and after hiding, the method can be very safe.As far as the authors know, there are two kinds of encryption techniques. One is based on frequency region, such as expanding frequency hiding, DCT hiding and sub_wave hiding, etc. By these methods the information is concealed into the high frequency heft of the carrier image code, which can not be observed by human eyes. Generally speaking, not much data can be concealed into a carrier image. The other is based on space region, a typical method to conceal information in the least significance bits (LSB); however, due to their unsafety, they are not important to the carrier image. This paper provides a method that can create redundant space in a color image by color quantization and hiding information in the MSB of the image. The method is better than that in LSB since the MSB is very important to the visual effect of the image.