Research On Information Hiding Using Natural Stego-cover

Information hiding has been applied in many areas,such as covert communication,copyright protection,identity authentication,and so on.Due to this,information hiding has also get a rapid development.However,the rapid development of information hiding has caused the development of steganalysis tools.The main idea of the steganalysis tools is to check whether there are some modifications left in the cover.If the modification exists,the cover may be hidden into secret information.The existence of steganalysis tools makes some traditional information hiding methods unsecure.To solve the problem,coverless information hiding has been proposed which has given a new idea to resist the steganalysis tools.However,on the one hand,the low capacity causes the impracticability of coverless information hiding methods based on text.On the other hand,the main idea of coverless image steganography is to build a mapping relationship between the secret message and image feature.This way causes the low capacity of those coverless image steganography methods.Meanwhile,the existing coverless image steganography method cannot hide the image directly as the secret message.Therefore,this paper proposed the solutions according to the above problems,as follows:According to the problem of coverless information hiding based on text,we propose a method,which can improve the capacity of those methods.We adopt to hide multiple keywords in one text.The problem of the method is that receiver does not know the number of keywords in each text.A mapping relationship has been built to convert the number of keywords to Chinese characters.Meanwhile,the number of keywords can be hidden into the same text by the same way.Thus,each natural stego-text can be hidden more than one keyword.Some experiments prove that the capacity can be improved.To solve the issues of those coverless image steganography methods,this paper innovatively apply the near-duplicate image retrieval in the coverless image steganography.This method makes the image as the secret message,and divides the secret image into several secret image patches which are the same size.Then,near-duplicate image retrieval is used to search for the image patch which is the most visually similar to the secret image patch,and denotes the image which contains the image patch as natural stego-image.This method can hide the image directly as the secret message.Some experiments prove that this method can improve the capacity.