Securing multi-media transmission over mobile communication channels

A novel Adaptive Lossy Image Compression (ALIC) technique is proposed to achieve high compression ratio by reducing the number of source symbols through the application of an efficient technique. The proposed algorithm is based on processing the discrete cosine transform (DCT) of the image to extract the highest energy coefficients in addition to applying one of the novel quantization schemes proposed in the present work. This method is straightforward and simple. It does not need complicated calculation; therefore the hardware implementation is easy to attach. Experimental comparisons are carried out to compare the performance of the proposed technique with those of other standard techniques such as the JPEG. The experimental results show that the proposed compression technique achieves high compression ratio with higher peak signal to noise ratio than that of JPEG at low bit rate without the visual degradation that appears in case of JPEG.

The security of digitally shared data like images, audio and video incurs many security and privacy-related challenges such as unauthorized access. In this work, a video encryption technique using improved sine map and DNA sequencing has been proposed. The proposed video encryption process mainly consists of three phases. In the first phase, key is generated using SHA-256. The second phase comprises of permutation of the video frame using SHA-256 key and improved sine map. In the final phase, diffusion is performed of the permutated frame by using SHA-256 and DNA sequencing, to obtain encrypted video. The experimental outcomes unveil that the obtained entropy of the encrypted video frames is approximately 8 that reflects high randomness in the encrypted frame, and it has low correlation coefficients among neighbouring pixels in all three horizontal, vertical and diagonal directions. The presented scheme of video encryption is resistant to threats like brute force attack, plaintext attack and statistical attack.

With recent advancements in multimedia technologies, the security of digital data has become a critical issue. To overcome the vulnerabilities of current security protocols, researchers tend to focus their efforts on modifying existing protocols. Over the last few decades, though, several proposed encryption algorithms have been proven insecure, leading to major threats against important data. Using the most appropriate encryption algorithm is a very important means of protection against such attacks, but which algorithm is most appropriate in any particular situation will also be dependent on what sort of data is being secured. However, testing potential cryptosystems one by one to find the best option can take up an important processing time. For a fast and accurate selection of appropriate encryption algorithms, we propose a security level detection approach for image encryption algorithms by incorporating a support vector machine (SVM). In this work, we also create a dataset using standard encryption security parameters, such as entropy, contrast, homogeneity, peak signal to noise ratio, mean square error, energy, and correlation. These parameters are taken as features extracted from different cipher images. Dataset labels are divided into three categories based on their security level: strong, acceptable, and weak. To evaluate the performance of our proposed model, we have performed different analyses (f1-score, recall, precision, and accuracy), and our results demonstrate the effectiveness of this SVM-supported system. INDEX TERMS Support vector machine (SVM), security analysis, image encryption, cryptosystem.

The transmission of digitized medical images over the existing telecommunications infrastructure presents a formidable challenge. To achieve delivery times on the order of seconds--as opposed to minutes or hours--for large-format high-resolution images, data compression on the order of 25:1 is necessary. This degree of data compression cannot be reached with lossless techniques. This paper reports on an adaptation of a standardized technique for lossy image compression (the JPEG approach), which provides high compression ratios for radiographic images with minimal apparent loss of diagnostic quality.

<p>Video Encryption is widely used in many real-time applications today. Despite numerous video encryption techniques that are available today, the challenges such as time and space complexity, real time latency, scalability and vulnerability towards few attacks still exist in the research domain, however few algorithms have achieved acceptable computational complexity, but in such cases vulnerability to certain attacks (differential, statistical, plain text attack, and cipher text attacks) are still a threat to secure video transmission. To the best of our knowledge, a comprehensive but detailed systematic literature review on video encryption is needed for the researchers in the scientific community. This paper, therefore, presents a systematic literature review of 30 scientific documents extracted from platforms like scopus and web of science. The paper, comprehensively addresses, various techniques of video encryption and encoding, different evaluation parameters to testify the performance of the algorithms and discusses the challenges of the existing video encryption algorithms. After careful investigation, it has been observed the approaches which involve encryption of the video data post the same has been encoded is the most efficient and scalable approach towards video encryption. In addition, it also implies that in near future, the proposed algorithms, must be evaluated based on the various categorization of parameters illustrated in this paper.</p>

Propagation characteristics of land mobile satellite communications channels have been studied actively. It is important to investigate the statistical characteristics of fade and nonfade durations as well as those of the fade depth for the design of practical communications systems. Probability density distributions of fade and nonfade durations and a new simulation model are described, based on data measured in Japan. It is shown that the statistical characteristics of fade and nonfade durations of the measured propagation data can be approximated very well with the sums of two log-normal functions. Man-made structures and artificial environments affect the fade and nonfade statistics, especially in freeways and urban areas. It is concluded that the proposed model can more adequately describe the fade and nonfade statistics than models proposed previously.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Multiple symbol differential detection of /spl pi//4 QPSK in land mobile satellite communication channels (modeled as correlated Rician fading) is studied. BER performance of this scheme in land mobile satellite communication channels are evaluated using union bounds of pairwise bit error probabilities for situations of ideal channel information and no channel information. It has been found that in light or medium fading Rician channels, about a 1 dB gain in E/sub b//N/sub o/ at a BER=10/sup -4/ can be achieved by using four-symbol differential detection instead of conventional two-symbol differential detection. It is also proved that multiple-symbol differential detection is not suitable for severe fading Rician channels or Rayleigh channels. The influence of the fading rate on the BER performance is also evaluated. Part of the results are compared with those from previous literature.

This paper considers the downlink performance of mobile communication channel based on a novel wireless infrastructure that is called stratospheric platforms (SPF). The SPF has been recently proposed as an alternative method for delivering mobile communication services such as IMT -2000 in parallel with cellular tower-based terrestrial system or satellite. Channel performance evaluation is now becoming a matter of urgency in the designing of communication link between the platform and mobile user. We first evaluate propagation characteristic in urban area in order to obtain propagation parameters in terms of path loss model and Rice factor. Due to their unique positioning, elevation and azimuth angle are considered as main parameter in SPF environment compared with terrestrial tower-based system. The propagation parameters are then used in order to evaluate downlink performance for IMT -2000 services served by the SPF. Different applications refer to different information bit rate that is carried by IMT -2000 system are considered in the analysis. In all scenarios, downlink performance decreases as the service bit rate increases and it becomes worse when elevation angle lower than 40deg.

An adaptive signal-to-noise ratio estimator in mobile communication channels

Encoder adaptable difference detection for low power video compression in surveillance system

A new video encoder proposal, H.26L, is compared against H.263 and H.263+. In the comparison, both computational complexity and compression performance are analyzed. Moreover, the trade-off possibilities between the complexity and compression performance within H.26L are presented. Experimental comparisons with H.263 and H.263+ show that H.26L reduces the output bit rate about 30% with the same quality. The computation time increases about three times compared to H.263 and leads into the encoding speed of 3-6 fps for QCIF sequences on a 400 MHz Pentium III processor. Realtime operation can be achieved by applying additional, algorithmic and platform-specific optimizations.

The huge usage of digital multimedia via communications, wireless communications, Internet, Intranet and cellular mobile leads to incurable growth of data flow through these Media. The researchers go deep in developing efficient techniques in these fields such as compression of data, image and video. Recently, video compression techniques and their applications in many areas (educational, agriculture, medical …) cause this field to be one of the most interested fields. Wavelet transform is an efficient method that can be used to perform an efficient compression technique. This work deals with the developing of an efficient video compression approach based on frames difference approaches that concentrated on the calculation of frame near distance (difference between frames). The selection of the meaningful frame depends on many factors such as compression performance, frame details, frame size and near distance between frames. Three different approaches are applied for removing the lowest frame difference. In this paper, many videos are tested to insure the efficiency of this technique, in addition a good performance results has been obtained.

A new method to assess the presence and the strength of the blurring artifact in video frames, without using a reference ideal image, is presented. The estimation is performed first through a global and simple measure over the whole picture, then through a finer, local analysis of the sharpness of the objects borders. The subjective relevance of the scene content is accounted for in choosing the image parts where this local blurriness measurement is performed. Relevant parts are selected using an existing measurement of the saliency of each pixel as well as a simple method to detect human faces, which are a particularly attracting content for the viewer. In the so selected parts, an objective measurement of the blurriness artifact is performed, based on the presence of fine detail and on the local edge width. Then the scene activity, or clutter, is measured by counting the number of distinct picture regions. In an active scene, indeed, a blurred object is deemed to be less apparent. The combination of quantified objective blurriness with clutter yields a final index, which proved to appropriately reproduce the judgements of human observers on images of different quality, resulting from different video encodings.

Real-time chaotic video encryption based on multi-threaded parallel confusion and diffusion

In this paper, we argue that significant performance benefits can accrue if integrated networks im-plement application-specific mechanisms that account for the diversities in media compression schemes.Towards this end, we propose a simple, yet effective, strategy called Frame Induced PacIcei Discarding,in which in which, upon detection of loss of a threshold number (determined by an application's videoencoding scheme) of packets belonging to a video frame, the network attempts to discard all the remain-ing packets of that frame. In order to analytically quantify the performance of FIPD so as to obtainfractional frame losses that can be guaranteed to video channels, we develop a finite state, discrete timemarkov chain model of the FIPD strategy. The fractional frame loss thus computed can serve as thecriterion for admission control at the network. Performance evaluations demonstrate the utility of theFIPD strategy. 1 Introduction The emergence of a variety of variable bit rate (VBR) video compression techniques (such as JPEGand MPEG) promise to drastically cut down the bandwidth requirements of video services. Whereasthe availability of high bandwidth networks make it feasible to support multiple video streams simul-taneously by reserving network resources (e.g., bandwidth and buffer space at the switches) to meetthe peak requirements of video streams, the statistical variations in video frame sizes yielded by thecompression schemes make such straightforward schemes highly inefficient. Consequently, schemes forefficient transmission of encoded video streams that rely on statistical multiplexing techniques to exploitthe variability in bandwidth requirements are gaining prominence.However, enhancing the network utilization by employing statistical multiplexing techniques mayyield occasional violations of the quality of service (QoS) requirements of video services (e.g., end-to-end delay, loss tolerance, etc.). In order to bound the magnitude of these violations, future integrated