A novel approach of secure communication based on the technique of speech information hiding

The proposed secure communication approach adopts the proposed algorithm of Analysis-By- Synthesis （ABS） speech information hiding to establish a Secret Speech Subliminai Channel （SSSC） for speech secure communication over PSTN （Public Switched Telephone Network）, and employs the algorithm of ABS speech information extracting to recovery the secret information, This approach is more reliable, covert and securable than traditional and chaotic secure communication.     

基于能量比调整的自适应音频信息隐藏算法

针对目前大多数音频信息隐藏算法无法抵抗移动通信系统压缩编码问题,利用GSM系统RPE-LTP编码前后相邻语音段,能量值之比基本保持一致的特点,提出了一种适用于GSM系统的音频信息隐藏算法,并且根据人类听觉系统的掩蔽效应,自适应地选择高能量语音段进行信息隐藏。实验结果表明,算法对常规攻击类型有较好的鲁棒性,尤其对GSM系统语音压缩编码有较强的抵抗能力;使用Logistic序列进行加密预处理,算法安全性良好;携密语音信噪比较高,具有良好的透明性。     

基于二级定位的编码信道信息隐藏算法

分析了以编码信道为载体的信息隐藏算法及容量,指出现有算法存在的问题,提出了一种结合容量上限判断的基于二级定位的信息隐藏算法。所提算法在秘密信息嵌入前首先计算系统隐藏容量上限,并判断是否超出;接着在嵌入位置选择过程中引入二级定位以及循环移位机制。仿真结果表明,相比已有算法,所提算法能较好地避免因隐藏容量过大而导致秘密通道暴露的风险;同时通过二级定位及循环移位机制提高嵌入位置的随机性,避免秘密信息相互覆盖,提升信息隐藏性能。     

一种基于混沌系统的窄带超低速语音加密算法

为了在极低通信速率信道中实现保密语音通信,在北大西洋公约组织的0.6 Kb/s增强型混合激励线性预测声码器算法基础上,提出了基于混沌映射的保密通信算法。算法利用两个Logistic方程产生混沌序列,对声码器码流进行置换和移位。最后对该加密语音通信系统进行了仿真测试。测试结果证明,系统方案切实可行,产生的密钥空间大,能够实现加密强度较高的语音保密通信。     

语音信息隐藏中的AERA算法

本文提出了一种能够在全球移动通信系统(Global System for Mobile Communications,GSM)中使用的信息隐藏算法——基于分析合成的能量比调整(Analysis-By-Synthesis Energy Ratio Adjust,AERA)算法.算法采用了分析合成(Analysis-By-Synthesis,ABS)技术,在嵌入过程中根据输入明文语音实时的调整嵌入强度,使得隐藏效果和解码效果都达到最佳值.大量仿真试验结果表明算法对GSM中的规则脉冲激励长期预测编码(Regular Pulse Excited-Long Term Prediction Coding,RPE-LTP Coding)、自适应差分脉冲编码调制(Adaptive Differential Pulse Code Modulation,ADPCM)等语音压缩编码以及滤波操作有很强的鲁棒性,携密语音的分段平均信噪比达到37dB,可以达到透明性要求.算法简单易行并且是基于盲检测的,具有很高的实用性.     

语音隐藏的研究及实现

本文提出了一种基于伪装式信息隐藏安全技术的语音信息隐藏电话（SIHT）系统的研究和实现方法。给出了语音信息隐藏的模型，并进行了模拟仿真。SIHT采用基于DSP的嵌入式技术设计了相应的功能模块。它可以利用普通的模拟电话线路，经过公共电话交换网络（PSTN），在不引起人们注意的普通通话中，通过系统建立的一条隐秘信道将保密信息顺利地传递到接收方。实验证明，SIHT可以在保证语音质量的条件下实现实时语音信息隐藏保密通信的功能。     

A novel covert speech communication system and its implementation

In this paper, a Covert Speech Telephone （CST） is designed and implemented based on the information hiding technique, which works on the internet. To solve the large embedding capacity problem for real-time information hiding, a steganographic system combined with a watermarking scheme is proposed, which skillfully transfers the secret speech into watermarking information. The basic idea is to use the speech recognition to significantly reduce the size of information that has to be transmitted in a hidden way. Furthermore, an improved DFT watermarking scheme is proposed which adaptively chooses the embedding locations and applies the multi-ary modulation technique. Based on the GUI （Graphical User Interface） software, the CST operates on both ordinary and secure mode. It is a completely digital system with high speech quality. Objective and subjective tests show that the CST is robust against normal signal processing attacks and steganalysis. The proposed scheme can be used in terms of military applications.     

一种基于Arnold置乱和DCT编码的无载体信息隐藏方法北大核心CSCD

近年来十分火热的搜索映射式无载体信息隐藏虽具有一定的鲁棒性,但其隐藏容量较低、传输负载大且算法复杂度高。针对以上问题,该文章提出一种基于Arnold置乱和离散余弦变换(discrete cosine transform,DCT)编码的无载体信息隐藏方法。该算法先对图片进行Arnold置乱,再对DCT后的低频系数进行编码,接着更换置乱参数来构建索引表。选择索引表中与秘密信息相同的编码值所对应的参数构建候选队列,最后筛选出鲁棒性强的参数作为密钥发送给接收方。实验结果表明,该方法与现有方法相比大大提高了嵌入容量,拥有更强的抗JPEG压缩性能。并且减少了传输负载,算法简捷,具有较强的应用价值。     

LPC analysis incorporating spectral interpolation for speech coding

A linear predictive coding (LPC) analysis scheme which is applicable to speech coding is proposed. The analysis method, called interpolative LPC (ILPC) analysis, estimates the spectral envelope by incorporating the interpolation characteristics into the LPC analysis. The ILPC analysis reduces average spectral distortion and the percentage of outlier frames, compared with the conventional LPC analysis followed by linear interpolation     

基于频谱特征的数字音频中信息隐藏算法

将需要保密的信息隐藏到数字音频信号或文件中可达到伪装的效果,是实现信息安全或保密通信的重要手段。文中设计了一种基于频谱特征的频域嵌入信息隐藏算法。介绍了该算法的基本处理流程,频域信息嵌入和提取的具体方法,并给出了对算法透明性、信息容量、鲁棒性的测试结果。文中算法可实现盲检测,实验表明其具有较好的透明性,对多种攻击的鲁棒性较好,并可实现一定码率下的无差错传输。     

Adaptive block transform coding of speech based on LPC vectorquantization

The authors describe several adaptive block transform speech coding systems based on vector quantization of linear predictive coding (LPC) parameters. Specifically, the authors vector quantize the LPC parameters (LPCVQ) associated with each speech block and transmit the index of the code vector as overhead information. This code vector will determine the short-term spectrum of the block and, in turn, can be used for optimal bit allocation among the transform coefficients. In order to get a better estimate of the speech spectrum, the authors also consider the possibility of incorporating pitch information in the coder. In addition, entropy-coded zero-memory quantization of the transform coefficients is considered as an alternative to Lloyd-Max quantization. An adaptive BTC scheme based on LPCVQ and using entropy-coded quantizers is developed. Extensive simulations are used to evaluate the performance of this scheme     

基于帧内预测模式的H.264/AVC视频信息嵌入算法

提出了一种基于帧内预测模式的H.264/AVC视频信息嵌入算法.在秘密信息进行嵌入时,根据人类视觉特性的掩蔽效应,筛选出I帧中纹理密集区域的4×4亮度块,确定为嵌入块.通过秘密信息调制4×4亮度块的预测模式最低有效位,完成秘密信息的嵌入.通过对算法进行仿真实验,证明本算法计算量小,能够实时处理.对视频载体影响小,有一定的嵌入容量,能够保证秘密信息的有效传输.     

Multipurpose speech watermarking based on multistage vector quantization of linear prediction coefficients

To make speech watermarking achieve both copyright protection and integrity verification, a novel multipurpose speech watermarking algorithm based on the multistage vector quantization (MSVQ) of linear prediction coefficients (LPCs) is presented in this article. The property of natural speech that the vector quantization (VQ) indices of the LPCs amongst neigh- boring frames tend to be very similar is utilized to embed the robust watermark in the indices of the first-stage VQ (VQ1). Then, the semi-fragile watermark is embedded in the indices of the second-stage VQ (VQ2) with index constrained VQ encoding scheme. Both the robust watermark and the semi-fragile water- mark can be extracted without host speech. Simulation results verify the effectiveness of the proposed algorithm in terms of robustness and semi-fragility.     

Short-term temporal decomposition and its properties for speechcompression

A technique of temporal speech compression, called temporal decomposition, is considered. A mathematical presentation of temporal decomposition is discussed from the point of view of speech production. Temporal decomposition is studied in terms of an iterative solution and its convergence. For vocoder applications, a practical algorithm, short-term temporal decomposition, is proposed. The statistical performance of this algorithm was tested on a multispeaker database. The efficiencies of vector quantization and vector predictability were comparatively studied on data derived from the algorithm and on data from linear predictive coding (LPC) analysis. The results show that data from the algorithm have more efficient information transmission via vector quantization than data from LPC, and that vector prediction coding is feasible for the data from temporal decomposition     

Rate-distortion speech coding with a minimum discrimination information distortion measure

An information theory approach to the theory and practice of linear predictive coded (LPC) speech compression systems is developed. It is shown that a traditional LPC system can be viewed as a minimum distortion or nearest-neighbor system where the distortion measure is a minimum discrimination information between a speech process model and an observed frame of actual speech. This distortion measure is used in an algorithm for computer-aided design of block source codes subject to a fidelity criterion to obtain a 750-bits/s speech compression system that resembles an LPC system but has a much lower rate, a larger memory requirement, and requires no on-line LPC analysis. Quantitative and informal subjective comparisons are made among our system and LPC systems.     

LDPC-CM-UEP在数字图像水印技术的应用

数字图像水印技术是一种信息隐藏技术。针对信息隐藏对于秘密信息隐匿性和可靠性传输的高要求,采用LDPC编码调制的不等差错保护（LDPC-CM-UEP）方案应用于数字图像水印技术中,将水印信息经过LDPC编码后的码字分为两部分,分别利用两种QAM高效调制方式,使水印信息作为重要比特得到很好的保护。仿真结果表明该方案在保证水印鲁棒性和隐匿性的前提下,提高了系统的频带利用率,从而改善了数字图像水印系统的传输质量。     

有序多重签名体制中阈下信道通信方法的研究

本文分析了阈下信道技术在数字签名中的应用，并以一种有序多重数字签名方案为例，对其中存在的宽带和窄带阈下信道进行了具体分析．提出了一种有序多重签名体制下的窄带阈下信道通信方案，通过实时性测试确定阈下信息位数，从而满足了传输信息容量与实时性的要求。     

A Novel High Capacity Reversible Information Hiding Scheme Based on Side-Match Prediction and Shortest Spanning Path

In recent years, information hiding techniques have attracted increased attention owing to the growing demand for the ability to exchange large amounts of information. In addition, hiding information in compressed messages is very practical in improving transmission efficiency and saving large amounts of storage space. However, the damage caused by hiding data in compressed messages reduces image quality more than the damage caused by hiding data in uncompressed messages. Hence, this paper proposes a data hiding scheme based on side-match prediction and declustering techniques for vector quantization (VQ) compressed images. The appropriate side-match prediction not only embeds secret information into the VQ index but also reverses the original compressed index. In addition, the capacity for secret information can be varied adaptively depending on the requirements of different applications. As experimental results indicate, the proposed scheme indeed outperforms previous work in hiding capacity and in the image quality of stego-images.     

A secure high capacity full-gray-scale-level multi-image information hiding and secret image authentication scheme via Tchebichef moments

The growth of image processing tools and applications has made it easy for multi-media content such as music, audio, and video to be manipulated or forged during transmission over the Internet. Efforts, such as information hiding in steganography, have been unable to secure data transmission and prevent its manipulation. Usage of coding theory, including cryptography, is not full proof in the sense that an unauthorized intruder may inject (tampering) and incorporate unintended data to the messages, which can tamper the transmitted data. There is a need for more transparent message information hiding schemes along with information content verification and authentication, as well as accurate tampering detection. In particular, as it is well known, in many current steganography methods, widely used for image information hiding, there are various technical challenges associated with hiding large amounts of image information in images. Some of these challenges relate to which locations, in a given carrier image, information has to be hidden in order to guarantee transparency of the resulting watermarked images, to the ability to extract hidden information accurately, to the performance of hidden secret information authentication and verification at the receiving end, to the dependency of the hidden information on a given carrier image, to the robustness of information hiding schemes to affine transformations such as rotation, and to the amount of data and number of full-scale images one can embed in a given single image carrier. Additionally, as it is well known, many of the existing stenography methods are based on the Discrete Fourier Transform (DFT), the Discrete Cosine Directors (DCT), or the Discrete Wavelength Transform (DWT) methods, which result in high Bit Error Rate (BER) of the extracted data. In this paper we present a secure high capacity image information hiding scheme where two full separate arbitrary full-scale gray level images (versus binary), one hidden information image and one authentication watermark image are hidden/embedded in the Tchebichef moments of a carrier image with very high imperceptibility. Here the second watermark image is used for identification and content integrity verification and authentication of the hidden secret image. Both the hidden secret hidden image and the authentication watermark image are of the same size as that of a given arbitrary carrier image. In particular, with the cost of computer memory getting lower and the bandwidth of transmission channels getting larger, we show how three different watermarked images, but the same to a naked eye, are produced and transmitted to achieve the desired advantages of high accuracy, security, authentication and verification of the recovered information. To the best of our knowledge, this two-full-scale gray images data hiding and hidden secret image information verification and authentication method is the first attempt of its sort. We show here the robustness of the proposed scheme to affine transformations such as rotation, scaling, and translation, the proposed scheme's high image malicious tampering detection and tampering localization and its high quality extracted recovered and authenticated hidden secret images. Additionally, in order to as much as possible keep the integrity of the received information, when watermarked images are rotated during transmission, a new image rotation estimation and recovery algorithm is presented as part of the proposed information hiding scheme. We show the effect of intended tampering attacks namely, cropping, noise, low-pass and high-pass filtering on the presented scheme. We also show how the extracted information accuracy is generally independent of the carrier image, and we present a mathematical analysis for characterizing the conditions under which transparency of the hidden embedded information is generally achieved for any given arbitrary carrier image. The case of how to extract the hidden information when one or two of the watermarked images is (are) lost is also tackled. Finally, experimental results on real images are presented to illustrate the efficiency and capabilities of the proposed method.     

MELP在数字对讲机基带系统中的应用

低速率语音编码技术是语音通信中重要的研究方向,在数字对讲机信道频率资源有限、复杂的传输环境下,具有广泛的应用前景.采用 TMS320VC5510数字信号处理器(DSP)作为硬件开发平台,结合MSP430微控制器和CC1101射频模块,对一种低成本、低功耗的民用数字对讲机的基带系统方案进行研究.实现数字对讲机中混合激励线性预测(MELP)低速语音压缩编码,结合 DSP 硬件特点进行算法优化,在满足实时性的要求下,得到了较好的语音质量.