Steganography, as one of alternative techniques for secure communications, has drawn more and more attentions. This paper presents a covert communication model based on least significant bits (LSB) steganography in Voice over IP (VoIP). The model aims at providing nice security of secret messages and real-time performance that is vital for VoIP. Therefore, we employ a simple encryption of secret messages before embedding them. This encryption strikes a good balance between adequate short-term protection for secret messages and low latency for VoIP. Furthermore, we design a structure of embedded messages. It can provide flexible length and avoid effectually both extraction attack and deceptive attack. We evaluate the model with ITU-T G.729a as the codec of the cover speech in StegTalk, our platform for study on covert communications theory in VoIP. In this case, the proposed model can provide two optional covert transmission speeds, i.e. 0.8 kb/s and 2.6 kb/s, where the maximum payload ratio is 99.98%. The experimental results show that our method has negligible effects on speech quality and well meets the real-time requirement of VoIP.

A Covert Communication Model Based on Least Significant Bits Steganography in Voice over IP

In order to optionally regulate embedding capacity and embedding transparency according to user’s requirements in voice-over-IP (VoIP) steganography, a dynamic matrix encoding strategy (DMES) was presented Differing from the traditional matrix encoding strategy, DMES dynamically chose the size of each message group in a given set of adoptable message sizes The appearance possibilities of all adoptable sizes were set in accordance with the desired embedding performance (embedding rate or bit-change rate) Accordingly, a searching algorithm that could provide an optimal combination of appearance possibilities was proposed Furthermore, the roulette wheel algorithm was employed to determine the size of each message group according to the optimal combination of appearance possibilities The effectiveness of DMES was evaluated in StegVoIP, which is a typical covert communication system based on VoIP The experimental results demonstrate that DMES can adjust embedding capacity and embedding transparency effectively and flexibly, and achieve the desired embedding performance in any case For the desired embedding rate, the average errors are not more than 0000 8, and the standard deviations are not more than 0002 0; for the desired bit-change rate, the average errors are not more than 0001 4, and the standard deviations are not more than 0002 6

Dynamic matrix encoding strategy for voice-over-IP steganography

Steganography is the art and science of data hiding. This article proposes an adaptive steganographic algorithm that embeds secret data in a compressed video stream using temporal and spatial features of the video signal and human visual system characteristics. Qualified-DCT coefficients of I-VOP and motion vectors of P-VOP and B-VOP are used for spatial and temporal features of the video, respectively. Embedded-data are extracted without using the original video and there is no need for full decompression. Experimental results demonstrate that the proposed algorithm has high imperceptibility and capacity. Furthermore, the bit rate remains approximately constant. © 2009 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 19, 306–315, 2009

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An adaptive scheme for compressed video steganography using temporal and spatial features of the video signal

Low bit-rate speech codec offers so many advantages over other codecs that it has become increasingly popular in audio communications such as mobile and Voice over Internet Protocol (VoIP) communications, and thus, researching steganography in low bit-rate speech codec is of important significance. In this study, we proposed a universal VoIP steganography model for low bit-rate speech codec that uses the PESQ deterioration rate and the decoding error to automatically choose a data-embedding algorithm for each VoIP bitstream, which enables ones to achieve covert communications using a low bit-rate speech codec efficiently and securely. Because no or little attention has been paid to steganography in Internet Speech Audio Codec, it was chosen as the test codec to verify the effectiveness, security, and practicability of the proposed steganography model. The experimental results show that, with the proposed steganography model, it achieved the average PESQ deterioration rate of 4.04% (less than 5%, indicating strong imperceptibility) and a high data-hiding capacity up to 12 bits/frame (400 bits/s, three times larger than other methods), and the proposed steganography model could effectively resist the latest steganalysis. Copyright © 2015 John Wiley & Sons, Ltd.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/sec.1183

Universal steganography model for low bit-rate speech codec

/pdf/an-adaptive-method-for-compressed-video-steganography-using-4m3vuwiwv2.pdf

An Adaptive Method for Compressed Video Steganography Using Temporal and Spatial Features of the Video Signal

This paper is dealing with steganography in DVD content. Classical steganography concerns itself on ways of embedding a secret message in a cover message such as a video stream or audio recording. The embedding is typically parameterized by a key. Without knowledge about this key, it is difficult for a third party to detect or remove the embedded material. Once sicret information was embedded in the cover object, this material is called a stego object [1], [2]. We embed a binary image in both video frames and audio tracks. This modification ensures higher payload and security.

S. Badura

Papers

Transform domain steganography in DVD video and audio content