Research On Automatically Changing Feature Technology Of Information Hiding

Information hiding technology help people to fulfill some special purpose by hiding information in the cover,which seems to be plain to others.The steganography is a branch of information hiding technology,it focus on improving imperceptibility and capacity,and it is often used for the purpose of secret communication.It is found that,among all steganographic software,some of them have such a weakness:they embed a fixed flag in the carrier in order to recognize themselves or locating the secret information for the purpose of extraction.In this way,they bring potential risks to themselves.Because the flag is usually fixed,the steganalizer may detect it in some way,and found there are some secret information in the stego-carrier.In order to solve this problem,by combining the time synchronization mechanism with chaotic systems,this paper proposes an automatically changing feature method based on chaotic encryption.With this method,the steganographic software can produce different flag each steganography processing to avoid their exposure.Specific tasks include the following aspects:1.This paper uses a time-based synchronization mechanisms.First,generate key by the time factor cooperating with an initial vector.Then use the generated key to produce the pseudo-random number.And the hiding locations of data is determined by the pseudo-random number.The time-based synchronization mechanisms has two advantages:First,each key is different from another;Second,when a key is lost or the time has been tampered or damaged,one can derive the key by the linear mechanism of the time.2.It combines the skew tent map and embedding algorithm,proposed an head flag hiding scheme.According to the length of flag,the sender and receiver need to negotiate a fixed length longer than that of flag.And the carrier is divided into blocks according to the fixed length.Then the flag is embedded into the blocks according to the pseudo-random number generated by the secret key.And thanks to the key which based on time and the chaotic systems,every sequence of embedding locations is almost independent of each other.By utilizing MATLAB software,this paper conducts simulation experiments to more than 1300 pieces grayscale images in 3 kinds of sizes.Including:experiments on key sensitivity analysis;comparisons between stego images and original images on their MSE and PNSR;experiments and analysis on the time complexity of recovery of key;experiments and analysis on the embedding method to encrypted images.According to these experiments and analysis,it concludes that the method proposed in this paper fulfills the mission of hiding the flag,and is able to recover the missing key in linear time complexity.And the method has little impact on robustness,imperceptibility and capacity of the original hiding algorithm.