Enhancing digital image integrity by exploiting JPEG bitstream attributes

The growth of modern wireless communications has increased the demand for high quality data services. This article presents an analysis of the performance of a DVB-S2 system with MIMO technology. A method for using a receiver-transmitter based on DVB-S2 with MIMO technology, provides a better quality of service for data transmission and discusses ways to improve the quality of data transmission using size and type converters of transmitting and receiving data, an amplifier and a normalizer Gain. The circuit was examined for bit error rate (BER) and peak signal-to-noise ratio (PSNR) between AWGN and multipath Rayleigh fading images operating under intersymbol interference (ISI). The analysis was carried out and a graph of the influence of ISI was obtained. The proposed system has the best quality of service for data transmission for fading channels. The transmission of images in the system includes a Rayleigh channel and AWGN with different values of the signal-to-noise ratio (SNR, dB) and different values of Gain. The Gain values change the BER and PSNR values (7.834 dB, 8.385 dB, and inf) at an SNR of -58 dB with respect to Gain values of 1, 32400 and 648000, respectively. Also obtained eye diagrams, where you can see a decrease in the negative impact of intersymbol interference with an increase in the value of Gain..This system can be used to wirelessly transmit higher quality, high-resolution radiological images (such as computed tomography or magnetic resonance imaging) over a wireless network to remote healthcare workers.

Currently, digital image watermarking is widely implemented as a tool for copyright protection. Along with technological developments, the technique of theft and manipulation of digital imagery increasingly sophisticated. So research on image watermarking should continue to grow for improved copyright security. This paper proposes the use of Discrete Cosine Transform (DCT) based on 8×8 sub-blocks to convert the original image from spatial to the frequency domain. The DCT transform result will produce AC and DC coefficients. Next, the DC coefficients are collected into a matrix to be transformed with DWT. The result of DWT transformation yield four subbands. Then the LL subband is selected for embedding copyright in the form of a binary image with a certain watermark strength value. The final step inverse the DWT-DCT transform to produce a watermarked image. From the results of this study, high imperceptibility values are evidenced by PSNR and MSE. Image watermark toughness is also measured by NC and is proven to be robust from various attacks mainly from JPEG compression attacks.

Recently, the major challenging attack is the side channel attack for both symmetric and asymmetric algorithm. Because in both cases, the secret key has to be sent out via a safe secured channel. The advanced encryption standard (AES) is mentioned as the best standard encryption algorithm by the US government, but there is one major attack on the AES that is the brute force attack. So, how to rule out these kinds of attack and how it is implemented effectively in hardware are being discussed in this paper. The honey encryption scheme is an effective algorithm, and it is also being discussed. In this paper, the detailed description of the AES and the methods to improve its speed and how it is integrated with the honey technique have been discussed. The different kinds of attacks and the various solutions are discussed for both of the algorithms. A survey of papers which has used these algorithms for various reasons with different perspective has been given. The honey algorithm creates the fake message for the wrong try of the key puncher. Thus, this is considered as the best algorithm, but it is also has some disadvantages that is also focussed in our survey. Copyright © 2017 John Wiley & Sons, Ltd.

In the technological era, the primary source of information is in the form of digital data, which has to be secured while storing or transmitting during communication over an unsecured network. Different approaches are used to provide security to digital data, viz. text, audio, image, and video. This paper initially explains the security system such as cryptography, watermarking, and steganography and their comparative analysis based on different characteristics, viz. satisfaction level of objective, type of carrier object and secret information to be used, dependency of security level, and quality assessment parameters. This review article focuses more on steganography methods applied over video. The various methods implemented for video steganography in compressed domain, viz. inter-frame and intra-frame prediction, motion vector estimation, entropy coding (CAVLC and CABAC), and transformed and quantized coefficients of DCT, DST, and DWT, etc. and the methods based on spatial and transform domain for uncompressed video are briefly described. It is followed by the detailed analysis of related work done by various researchers in video steganography and the obtained experimental results. Furthermore, the confidential data hiding in compressed videos are explained using Moving Picture Expert Group (MPEG—1, MPEG—2, MPEG—4), Advanced Video Coding (AVC)/H.264, and High-Efficiency Video Coding (HEVC)/H.265 that includes both spatial and transform domain. This paper summarizes and explains the detailed investigations of numerous techniques of video steganography based on the comprehensive literature survey. The methods used to assess the performance of video steganography are analyzed based on the quality assessment parameters such as imperceptibility; measured by peak signal to noise ratio (PSNR), mean square error (MSE), and structural similarity (SSIM), robustness; measured by bit error rate (BER) and similarity (Sim), and embedding capacity; measured by hiding ratio. The overall review of past literature facilitates to have in-depth knowledge for upgrading the video steganography.

A coding layer robust reversible watermarking algorithm for digital image in multi-antenna system

Integration of MANET with the Internet is a challenging problem. It is important that dynamically deployed wireless ad hoc networks should also gain access to Internet multimedia contents through these fixed networks. When a mobile node in an Ad Hoc network wants to communicate with a node on the Internet, it has to find an efficient and reliable Internet gateway. For this purpose, the node either can send solicitation message or may depend on periodic gateway advertisement. Gateway discovery time has strong influence on packet delay and throughput. In most of the cases, a mobile node uses a number of physical hops to a gateway to communicate with a fixed host connected to an Internet. However, a minimum hop path may not always be efficient if some nodes along the path have longer queue of waiting packets. The focus of this paper is on devising an efficient proactive gateway discovery algorithm that takes into account the size of interface queue in addition to the traditional minimum hop metric to select an efficient gateway. In the MANET domain, AODV routing protocol has been used. This approach also allows an efficient handoff from one gateway to another gateway and still maintains a seamless connectivity to a fixed host. In this paper, impacts of this new metric on the gateway discovery performance are investigated. Simulation results indicate that our protocol outperforms other approaches.

With images replacing textual and audio in most technologies, the volume of image data used in everyday life is very large. It is thus important to make the image file sizes smaller, both for storage and file transfer. Block Truncation Coding (BTC) is a lossy moment preserving quantization method for compressing digital gray level images. Even though this method retains the visual quality of the reconstructed image it shows some artifacts like staircase effect, etc. near the edges. A set of advanced BTC variants reported in literature were analyzed and it was found that though the compression efficiency is increased, the quality of the image has to be improved. An Improved Block Truncation Coding using k-means Quad Clustering (IBTC-KQ) is proposed in this paper to overcome the above mentioned drawbacks. A new approach of BTC to preserve the first order moments of homogeneous pixels in a block is presented. Each block of the input image is segmented into quad-clusters using k-means clustering algorithm so that homogeneous pixels are grouped into the same cluster. The block is then encoded by means of the pixel values in each cluster. Experimental analysis shows an improvement in the visual quality of the reconstructed image with high Peak Signal-to-Noise Ratio (PSNR) values compared to the conventional BTC and other modified BTC methods.

Low complexity energy efficient very low bit-rate image compression scheme for wireless sensor network

Face de-identification aims at preserving the privacy of people by concealing faces in images and videos. In this paper, we propose a defeating algorithm for face de-identification methods that are based on DCT-block scrambling. These methods protect faces by scrambling the AC and DC coefficients of the DCT blocks corresponding to a face region in the compressed domain. The proposed approach does not make use of the protection key utilized in the de-identification process. It consists of the following stages. First, random unprotected faces are generated based on a random alteration of the sign of AC coefficients with a fixed value of DC coefficients. Then, the best unprotected faces are selected by an eigenfaces model trained with facial images from a repository of potentially protected people. A single facial image is then generated by merging the selected images through median stacking. Finally, the eigenfaces model is utilized again to choose the face from the repository that is closest to the resulting image in order to improve the aspect of the unprotected face. Experimental results using a proprietary database and the public CALTECH, Utrecht and LFW face databases show the effectiveness of the proposed technique.

This paper investigates a novel image enhancement technique based on statistical analysis of DCT coefficients. The proposed method treats the DC coefficient and AC coefficients of a DCT block separately to arrive at two different scaling factors. Since the DC coefficient of a block being an average value concerns with illumination of the image, the coefficient of variation (c v ) is estimated which is used as the DC scaling factor. On the other hand, since the AC coefficients concern with the local contrast, these are analyzed diagonally forming bands followed by calculating entropy and contrast which are utilized to arrive at the AC scaling factor. The two scaling factors are used to compute the enhanced DCT block and the corresponding enhanced image. Our experimental results show that such statistical analysis is able to capture the behaviour of the DCT coefficients which is exploited to arrive at the scaling factors thereby making the proposed method independent of predefined enhancement functions like twicing function, S-function currently utilized by state-of-the-art methods. Extensive testing and comparative analysis of the proposed method clearly shows better results in comparison to an existing technique.

Steganography plays a vital role in the field of covert communication. This paper proposes a novel embedding scheme which embeds secret data adaptively. The proposed scheme employs integer to integer Lifting Wavelet Transforms (LWT) and pixel strength to specify suitable locations for data embedding. The integer LWT eliminates distortions, which is produced because of rounding process in the convolutional wavelet transforms. The performance of the proposed scheme is addressed using image quality metrics based on Peak Signal To Noise Ratio (PSNR) versus embedding ratio. Moreover, Bit Error Rate (BER) is utilized to assess robustness of the scheme. The experimental results show that the proposed is superior over several embedding techniques such as embedding based convolutional wavelet transforms and Lest Significant Bits (LSBs). The range of PSNR is gained between 51.52 and 22.15dB for range of embedding rate between 5% and 35%. Furthermore, the technique results error free for retrieving of secret data. In addition to the above features, the proposed technique increases security level of embedded data due to adaptive embedding process that increases randomly of embedding locations. The proposed scheme can be used in several important applications such as bank tag for authentication, military communications. Also, it can be implemented easily as a hardware chip and combine with covert imaging systems.

With the development of the wireless communication technology and the popularity of mobile devices, the mobile wireless network (MWN) has been widely used in our daily life. Through the access point (AP), users could access the Internet anytime and anywhere using their mobile devices. Therefore, MWNs can bring much convenience to us. Due to the limitation of APs coverage, the seamless handover frequently occurs in practical applications. How to guarantee the users privacy and security and identify the real identity when he/she brings harm to the system becomes very challenging. To achieve such goals, many anonymous handover authentication (AHA) protocols have been proposed in the last several years. However, most of them have high computation costs because mobile nodes need to carry out the bilinear pairing operations or the hash-to-point operations. Besides, most of them cannot satisfy some critical requirements, such as non-traceability and perfect forward secrecy. In this paper, we first outline the security requirements of AHA protocols, and then propose a new AHA protocol to eliminate weaknesses existing in previous AHA protocols. Based on the hardness of two famous mathematical problems, we demonstrate that the proposed AHA protocol is secure against different kinds of attacks and can meet a variety of security requirements. It can be seen from the details of implementations that the proposed AHA protocol also has much less computation cost than three latest AHA protocols.

In this chapter, a successful attempt for transmission of secured compressed data over GSM voice channel has been made. In this work, given text of any length is converted to real-time speech signal and then compressed with discrete wavelet transform, encoded with gold code sequence, modulated using quadrature phase-shift keying and sent over the GSM voice channel. The aim of this paper was to present a secured digital data compression and modulation for robust data transmission in terms of voice. The main objective was to achieve higher data rates, lower bit error rate, and less utilization of the bandwidth. The performance of the proposed technique is compared to an already existing technique for data transmission over voice channel. It has been observed that the proposed technique shows much better results in terms of bit error rate (BER), mean square error (MSE), and peak signal-to-noise ratio (PSNR) as compared to the already existing techniques. The proposed scheme has a great significance in GSM systems where data security and quality of service (QoS) are two main issues.

Security and privacy of EMI images while being transmitted over an insecure medium or when stored on third-party storage. In this paper, an enhancement of the EBS steganography with four layers of cryptography has been implemented to ensure the secrecy and privacy of a large and diverse data set of X-ray images available in JPEG format. The major objective of this research is to secure a large and diverse data set of EMI into a cover image without degrading the EMI quality as these can be used for future medical referencing. A data set of 5856 varying dimensioned and sizes X-ray images is hidden one at a time around the Edge of the normalized cover image Lena using edge-based steganography. The algorithms with various performance evaluation tests such as Computational Time is 0.135217 seconds for creating one stego-crypto-image, Peak Signal to Noise Ratio (PSNR) is 74.55838892 dB, Mean Square Error (MSE) is 3.50075E-08, Bit Error Rate (BER) is 2.25493E-05, SSIM is 0.46291047, etc. The results obtained showed less computational time, while quality tests such as BER, and SSIM ensure that the image extracted is the same as the original hence better performance and reduction in computational time.

A novel COntent-Based Rate-Adaptation (COBRA) model is proposed to improve the quality of video transmission over multiple-input multiple-output (MIMO) system with channel state information feedback (CSI). The model captures relationships among the video content type, video sub-stream bit-rates, achievable peak signal-to-noise ratios (PSNR), and channel bit error rate (BER). COBRA facilitates joint selection of physical layer parameters and video sub-stream configuration. Unlike existing methods, the COBRA model offers an efficient way of balancing losses in PSNR due to channel errors and non-transmission of some enhancements layers in a sub-stream, with a judicious mechanism of selecting sub-stream configurations and communication parameters. Simulations show that COBRA maintains video quality at acceptable levels over wide range of low channel signal-to-noise ratio (SNR) values. It achieves the same video PSNR as obtained by the complete stream transmission at 10 dB higher channel SNR.