Research On Covert Communications And Evaluation Method Of Voice-over-IP Using Mixed Wet Paper Code

Information hiding technology is one of the important branches in the emerging field of information security.As a real-time and highly reliable service,VoIP has been widely used in many commercial streaming media communications.With the increasing use of VoIP,the stealth communication technology with VoIP as steganographic carrier has gradually become a new research hotspot.Therefore,VoIP voice stream is selected as steganographic carrier in this paper to deeply study the security and steganographic performance of VoIP covert communication,and to explore a variety of steganographic methods based on VoIP covert communication.Major initiatives includeFirstly,choose different media from information hiding as steganographic carrier's perspective,analyzes the exist in the information hiding based on static media limitation,which leads to choose based on dynamic VoIP streaming media as steganographic carrier has more application prospects of advantage,this paper expounds the concept of information hiding,and introduces the current domestic and foreign in different steganographic carrier of information hiding technology research status.Secondly,there is still no universal evaluation method for the security of VoIP streaming media covert communication,so a security evaluation method for VoIP streaming media covert communication is proposed based on the existing performance indexes.The basic idea is based on the secret communication principle of VoIP streaming media,and the five security indexes and corresponding quantification standards of secret communication of VoIP streaming media are given.And through the analysis of different VoIP covert communication examples to verify its effectiveness,the theoretical and experimental results show that the method can effectively help the system administrator to evaluate the security performance of VoIP covert communication and has good universalityThirdly,in order to solve the problems of low embedding efficiency and low concealment of traditional steganography,it cannot meet the security requirement of hidden information of VoIP streaming media covert communication.So F5 coding in matrix coding and the improved wet paper coding are combined,and a VoIP steganography method based on enhanced mixed wet paper coding is proposed.The experimental results show that the proposed method can not only maintain the transparency of the carrier,but also improve the embedding efficiency of the secret informationFinally,from the point of view that the performance of each hidden bit in coded speech frame is not equal,a steganography method for VoIP based on hidden performance classification mixed wet paper code is proposed.The basic idea is that on the basis of performance classification of hidable bits,combining the strategies of STC code and wet paper code,supplemented by LSB replacement idea,the corresponding hiding level is selected to embed hidden information.Experimental results show that the proposed method has good imperceptibility and better steganography performance than the existing methods.