Visual Security Research Articles

Visual Quality Assessment for Perceptually Encrypted Light Field Images

Perceptual encryption has received widespread attention as a technology for protecting multimedia visual information. In multimedia applications, perceptual encryption only protects a portion of the content without previewing all the information. At present, perceptual encryption is mostly oriented to conventional plain images while few methods aim at visual security measures for perceptually encrypted images. Existing solutions usually adopt well-known quality assessment metrics to measure the visual quality of encrypted images. However, they often exhibit undesired behavior on perceptually encrypted images with low quality. As a typical representation of three-dimensional scenes, light field images record the intensity and direction of light during propagation which is distinct from 2-D images. In this paper, we construct a perceptually encrypted light field image database (PE-LFID) for quality assessment based on 14 reference light field plaintext images. For each scene, we employ four encryption methods, each of which has six levels. Additionally, a novel visual security evaluation method based on PE-LFID is proposed by taking into account the local and global features of the light field images. First, we use a multi-threshold edge detection method to obtain the edge similarity in the spatial domain of the light field image. Afterwards, the epipolar plane image (EPI) generated from the angular domain of the light field image is used to calculate the gradient magnitude similarity, which is expressed as a global feature. Furthermore, the final quality prediction score is calculated by adaptively weighting between local and global features. We conduct extensive experiments on the proposed PE-LFID to assess the performance of classical and state-of-the-art IQA models. The experimental results demonstrate the effectiveness of the proposed method for visual security evaluation of perceptually encrypted light field images, as well as the scalability of PE-LFID.

A novel selective encryption scheme for H.264/AVC video with improved visual security

As cloud storage becomes more popular, concerns about data leakage have been increasing. Encryption techniques can be used to protect privacy of videos stored in the cloud. However, the recently proposed sketch attack for encrypted H.264/AVC video, which is based on the macroblock bitstream size (MBS), can generate the outline images of both intra-frames and inter-frames from a video encrypted by most existing encryption schemes; thus, the protection of the original video may be considered a failure. In this paper, a novel selective encryption scheme for H.264/AVC video with improved visual security is presented. Two different scrambling strategies that do not destroy the format compatibility are proposed to change the relative positions between macroblocks in intra-frames and inter-frames respectively, which in turn substantially distort the sketched outline images so that they do not disclose meaningful information. Moreover, the sign bits of non-zero DCT coefficients are encrypted to contribute to the visual security of our scheme, and an adaptive encryption key related to the intra prediction mode and the DCT coefficient distribution of each frame is employed to provide further security. The experimental results show that our encryption scheme can achieve a better visual scrambling effect with a small adverse impact on the video file size. Furthermore, the security analysis demonstrates that our scheme can successfully resist the MBS sketch attack compared with other related schemes. The proposed method is also proven secure against some other known attacks.

A Novel Analysis of Advanced Visual Cryptography Techniques for Providing Security Against Web Attacks Using Support Vector Machine Technique

In today’s internet applications such as some real time application services like core banking and other public service oriented application have been major issue in authentication of user specification. To perform online dictionary attacks, passwords have been used for security and authentication mechanism. Present days, hacking of databases on web oriented applications is unavoidable to access them easily. Data maintenance is a complex task in internet applications. To solve these type of problems in internet applications, in this paper, we proposed a novel Integrated and Dynamic CAPTCHA (Completely Automated Public Turing Test to Tell Computers and Humans Apart) (I&D CAPTCHA), which is extension version of existing CAPTCHA that valuated third party human attacks in internet applications based Visual Cryptography approach to discuss about authentication problem in real time applications. There is more number of methods presented for security in advanced pictures for insurance from inventive uninvolved or dynamic assaults in system correspondence environment. Like insightful Visual Cryptographic (VC) is a cutting edge strategy, which is utilized to mystery picture safely impart furthermore keep up to privacy. To proceed with difficulties of security in advanced picture information sharing, so in this paper we break down various VC security instruments for computerized picture information offering to regard tomystery information secrecy. Our examination give effective security answers for relative mystery advanced picture information imparting to correspondence progressively environment. Security aspects are main concepts in present days because of increasing statistical data storage. In Artificial Intelligence (AI) oriented applications, it is very difficult in terms of protection to increasing new aspects in real time world. So we also plan a Novel and Advanced Security system to enable solution for basic AI problems in this paper. This framework mainly works based on Captcha as visual security passwords (CaRP); it is two way communication plan which means that, it is the combination of Captcha and visual security plan. Our approach mainly worked with image security with respect to selection of passwords based on random way. In this paper, we also propose AMODS, an adaptive system that periodically updates the detection model to detect the latest unknown attacks. We also propose an adaptive learning strategy, called SVM HYBRID, leveraged by our system to minimize manual work. Our system out performs existing web attack detectionmethods, with an F-value of 94.79% and FP rate of 0.09%. The total number of malicious queries obtained by SVM HYBRID is 2.78 times that by the popular Support Vector Machine Adaptive Learning (SVMAL) method. The malicious queries obtained can be used to update the Web Application Firewall (WAF) signature library.

It's a man's world: carnal spectatorship and dissonant masculinities in Islamic State videos

Abstract Islamic State videos have often been associated with savage violence and beheadings. An in-depth scrutiny however reveals another striking feature: that female bodies are absent, blurred or mute. Examining a few Islamic State videos in depth, the article suggests that the invisibility of women in tandem with the ostentatious visibility of male bodies enable gendered and embodied spectators to indulge in homoerotic as well as heterosexual imaginaries. In contrast to studies on visual security and online radicalization which assert that images affect an audience, this article focuses on the interaction between video and audience and argues that spectators are not only rational and emotional but embodied and gendered as well. Islamic State videos do not only attract western foreign fighters through religious–ideological rhetoric or emotional impact but also through gendered forms of pleasure and desire that enable carnal imagination and identification. The article probes the analytical purchase of carnal aesthetics and spectatorship.

Secure Data Hiding using Reversible Image Transformation

In today’s era, the large amount of data’s are stored in cloud. But nowadays securely storing data to the cloud is an important task. But the unauthorized parties are tries to decrypt the data from the cloud. So, the data stored in cloud should be secure from any malicious activities. Based on these requests, we propose a framework named reversible data hiding (RDH). It mainly works on encrypted images based on reversible image transformation (RIT). The server insert data into the cloud. On that time, he will add some additional information for the protection of data. In the given framework, the original data can be embedded in another image named carrier image with equal size. So, the hacker tries to pullout the data, he will only get the carrier image. So we can accommodate more data’s into a single storage space. The method picks the data to be hide and a carrier image with equal size. The cover image is embedded into the original image based on the LSB insertion algorithm. i.e., the original data’s are dissolved into the carrier image using a secret hiding key. The cover image is encrypted using blow fish encryption algorithm. It includes normal RDH method and RDH with RIT. Using RIT, it gives high visual quality and security. The technique is mainly used in medical imagery, military imagery for reliable data storage.

A visually secure image encryption scheme based on semi-tensor product compressed sensing

In traditional compressed sensing (CS), the measurement matrix always faces problems such as large data storage, high memory usage and a large amount of data calculation. To reduce the storage space of the measurement matrix, improve memory usage and reduce the amount of data, this paper proposes a CS strategy based on a semitensor product (STP). The STP is employed to sample a sparse matrix from the measurement matrix, and Arnold scrambling is used to increase the security of the secret image. Furthermore, a visual security strategy for the secret image is employed to transform it into a visually meaningful image. The simulations show that the proposed visual security strategy based on STP-CS can not only greatly reduce the storage space occupied by the measurement matrix but also maintain high reconstruction quality compared with the traditional CS model while ensuring visual security quality.

Faceted gratings for an optical security feature.

A method of optimizing and manufacturing a diffractive blazed grating array (DBA) is proposed to create a visual security feature when illuminated by a divergent light-emitting diode source. A pure phase grating array serving as the optical security component consists of blazed grating cells with the same size, 75 µm. After a divergent spherical wave is decomposed into harmonic waves, each grating cell of the DBA locally deflects the harmonic-waves into predefined directions and forms a feature pattern on the target plane. Particularly, a two-step optimization method is further developed for optimizing the period and orientation of each grating cell. The DBA sample is fabricated by using our home-built parallel direct-write photoplotter with a resolution of 0.75 µm. Both numerical simulations and optical experiments are demonstrated to validate the proposed model. Since the optical security component developed is a surface relief structure of a single polymer material, it can be replicated for mass production by using standard roll to roll nanoimprint technology. The design algorithm proposed in this work will enable the extension of the optical security elements to a broader realm and facilitate extensive developments in other research fields of the optics community, such as light-shaping, specific illumination for lithography, and microscope systems.

Advanced graphical-based security approach to handle hard AI problems based on visual security

Security is the main aspect to explore human data from different web oriented applications present in artificial intelligence (AI). It is very difficult to use different web applications without security to access data in various places. So that various types of security related approaches were introduced to use services in securely in outside environment, but they have some limitations to protect data from outside attackers (hackers). So that in this paper, we propose and introduce a novel and advanced security model to provide security from outside attackers in AI related web oriented applications. In this approach, we follow the basic features related to Captcha as a graphical password to enable security services in our proposed approach. Using Captcha graphical passwords in our approach, we describe pushing attacks, pass-on attacks and guessing attacks in web applications with random selection of Captcha passwords to use web services. Our experimental results show efficient security relations when compare to existing security approaches in terms of Captcha generation, time and other parameters present in web security applications.

Advanced graphical-based security approach to handle hard AI problems based on visual security

Security is the main aspect to explore human data from different web oriented applications present in artificial intelligence (AI). It is very difficult to use different web applications without security to access data in various places. So that various types of security related approaches were introduced to use services in securely in outside environment, but they have some limitations to protect data from outside attackers (hackers). So that in this paper, we propose and introduce a novel and advanced security model to provide security from outside attackers in AI related web oriented applications. In this approach, we follow the basic features related to Captcha as a graphical password to enable security services in our proposed approach. Using Captcha graphical passwords in our approach, we describe pushing attacks, pass-on attacks and guessing attacks in web applications with random selection of Captcha passwords to use web services. Our experimental results show efficient security relations when compare to existing security approaches in terms of Captcha generation, time and other parameters present in web security applications.

A User-centered Design Approach to Near Field Communication-based Applications for Children

There is an abundance of technology targeting children in terms of education, entertainment, and health; however, little research has been conducted on the usability of Near Field Communication (NFC) to create an interactive, digital environment for children easily accessible on a mobile device. NFC technology is a component of Radio Frequency Identification (RFID) technology and is affordable, intuitive, and accessible. The following research evaluates existing NFC applications for children in terms of their ease of use, appropriateness, and areas in need of improvement. Recommendations are provided in visual design, audio enhancements, reward system, and privacy and security concerns. It is concluded that adopting NFC technology in all facets of life will positively benefit the most vulnerable population, children, but first progress toward a user-centered design for this group is required.

Visual Security Evaluation of Perceptually Encrypted Images Based on Image Importance

Perceptual/selective encryption has been gaining widespread attention as an emerging technology for image privacy protection. However, few studies focus on the visual security evaluation of perceptually encrypted images, which has a significant impact on measuring the effectiveness and practicality of these encryption methods. In this paper, we propose an image importance-based visual security index (IIBVSI) by leveraging spatial contrast and texture features. Based on the characteristics of perceptually encrypted images, we present an averaged high-order gradient magnitude map to describe the spatial contrast feature and introduce a combined local amplitude map of multiple log-Gabor filters to represent the texture feature. Specifically, the multiresolution representation of an image is first created by downsampling to simulate the hierarchical property of the human visual system. Next, for each scale of image resolution, the spatial contrast and the texture feature maps are extracted from both plain and encrypted images. Similarity measurements are then conducted on these feature maps to generate the contrast and the texture similarity maps. An image importance-based pooling strategy is subsequently proposed to combine these measurements and generate a visual security score. The final IIBVSI score is computed by averaging the visual security scores of all scales of image resolution. Extensive experiments are conducted on several publicly available databases, and the results demonstrate the superiority and robustness of our proposed IIBVSI compared with existing state-of-the-art work in the low and moderate image quality ranges.

A High Quality Steganography Method with Twenty Five-Pixel Value Differencing

The fundamental objectives of image steganography algorithm are to simultaneously achieve high payload or embedding capacity, good visual imperceptibility and security. This paper presents a new approach to improve the embedding capacity and provide an imperceptible visual quality, a novel steganography method based on algorithm twenty five pixel value differencing and modified interval table (TFPVD). The cover image is made into 5×5 blocks that don’t overlap and TFPVD method with modified interval is used to embed and extract secret information. The results showed that the proposed TFPVD steganography algorithm has a higher steganographic capacity, which is 1,764 times that of the PBVD algorithm.

PEID: A Perceptually Encrypted Image Database for Visual Security Evaluation

Perceptual image encryption provides an efficient and effective way to preserve the confidentiality of visual information, and the measurement of content leakage is of fundamental importance for perceptually encrypted images. Numerous visual security indexes (VSIs) have been proposed to evaluate visual content leakage. Due to the lack of perceptually encrypted image databases, image quality assessment (IQA) databases are widely adopted to evaluate the performance of existing VSIs. However, there are huge differences between VSIs and IQAs. The misuse of databases may lead to an inaccurate evaluation. In this paper, we propose a perceptually encrypted image database (PEID) which contains 1080 encrypted images from 20 plain images with 10 well-known perceptual encryption techniques. Both visual quality and content leakage scores of the encrypted images are obtained through a comprehensive subjective evaluation. We also propose a systemic methodology to accurately evaluate the monotonicity, fitness, and accuracy of VSIs. We conduct extensive experiments on the proposed PEID to evaluate the performance of existing state-of-the-art VSIs. We have made the database publicly available for download and hope that the proposed PEID can facilitate the research of visual security evaluation and beyond.

Visual hacking – why it matters and how to prevent it

To be truly comprehensive, security management strategies need to include prevention of visual security breaches – the ability to physically view and even photograph sensitive or confidential information. Visual privacy is either specified or implicit within a variety of regulations and industry-specific guidelines, and one area that is gaining considerable attention is preventing unauthorised viewing of sensitive or confidential information on digital screens.

Visual security studies: sights and spectacles of insecurity and war

Visual security studies: sights and spectacles of insecurity and war

How do Internet memes speak security?

Recently, scholars have worked to widen the scope of security studies to address security silences by considering how visuals speak security and banal acts securitise. Scholarship on internet memes and their co-constitution with political discourse is also growing. This article seeks to merge this literature by engaging in a visual security analysis of ‘everyday’ memes. A bricolage-inspired method analyses the security speech of memes as manifestations, behaviours and ideals. The case study of Pepe the Frog highlights how memes are visual ‘little security nothings’ with power to speak security in complex, polysemic and ambiguous ways which can reify or challenge wider security discourse.

The civilian's visual security paradox: how open source intelligence practices create insecurity for civilians in warzones

ABSTRACTImages taken by civilians and shared online have become an important source of conflict intelligence. This article explores issues around how states and non-state actors appropriate civilians’ images to produce intelligence about conflict, critically scrutinizing a practice often called open source or social media intelligence. It argues that image appropriation for open-source intelligence production creates a new kind of visual security paradox in which civilians can be endangered by their everyday visual practices because their digital images can be appropriated by outside actors as conflict intelligence. The transformation of everyday images into conflict evidence relies on what Barthes termed the photographic paradox, the paradox that while a photograph is clearly not the reality it depicts, the photograph is casually interpreted as a copy of that reality. When images are appropriated as conflict intelligence this photographic paradox translates into a security paradox. A visual security argument can be made without the intention or knowledge of the image producer, who then comes to perform the role on an intelligence agent. Yet civilians in warzones can hardly refrain from producing any images when they need to call attention to their plight, and to stay in contact with friends and relatives. The paradox, then, is that such vital visual signs of life can rapidly become sources of danger for the civilian. This civilian visual security paradox, it is argued, demands that intelligence actors respect the protected status of civilians in their online collection practices. So far, however, there is little sign of such respect.

Integrated visual security management for optimal condition explorations in resource-constrained systems

As more and more mobile video applications contain important and private video data, various video encryption techniques have been proposed to protect them. Many of those applications typically utilize the standard video compression while running on mobile platforms which have limited amount of resources. Therefore, we need to consider not only the protection but also the compression and the energy in the mobile video applications. Accordingly, the selective video encryption which protects partial data within the standard video compression has been challenging thanks to format compliance and low computational complexity. However, various parameters of the video compression and the video encryption result in different amount of visual security, compression efficiency, and energy efficiency. Further, it is difficult to find the one solution to maximize all those performance indices at once since there exist tradeoff relationships among them. Therefore, based on the tradeoff relationships, design space exploration should be required to find the interesting parameter set under the given requirements. For the efficient design space exploration, we propose the BEVS (bitrate and energy-bound visual security) to examine each Joint Video Compression and Encryption scheme in terms of the visual security, the compression efficiency, and the energy efficiency. Utilizing the proposed BEVS in our experimental design space, we achieve up to 36.7% visual security improvement under the empirical budgets.

Meaningful Encryption: Generating Visually Meaningful Encrypted Images by Compressive Sensing and Reversible Color Transformation

Recently, compressive sensing (CS) and visual security (VS) have caught researchers attention in information security field. However, the measurement matrix is often reused in CS, which makes it vulnerable to chosen plaintext attack (CPA). In addition, when generating meaningful cipher images, the size of the carrier image is usually not less than the size of the plain image. In order to overcome these drawbacks, a new visually secure image encryption scheme using CS and reversible color transformation is proposed. The algorithm consists of two stages: compression and embedding. In the first stage, chaotic sequence is used to generate different structurally random matrices. When CS is performed, a random number is added during the process of sampling. By choosing different random numbers, different measurement matrices can be used to compress and encrypt the same image in different order. In the second stage, block pairing, color transformation and block replacement are employed to obtain a meaningful image. Different from the block replacement between two similar images, this paper first attempts to replace the block of the carrier image with a compressed noise-like image block. Thus, the carrier image can be smaller than the plain image, which saves the bandwidth of transmission. Both theoretical analysis and experimental results show that the proposed encryption scheme has good encryption performance, can effectively resist common attacks, and is suitable for meaningful image encryption.

A visually secure image encryption scheme based on parallel compressive sensing

Abstract It is generally recognized that encrypting an original image into meaningless cipher image is an ideal method to protect image information. However, during transmission, the meaningless cipher image would draw attention and thus attract attacks. Recently, compressive sensing (CS) and carrier images have been utilized by Chai et al. to construct a novel image encryption scheme with visual security. However, in this scheme, some extra transmission is required for possible decryption besides the encrypted image. Moreover, the imperceptibility of the cipher image can be further improved and the recovered image quality would be severely degraded if unsuitable carrier images are selected. In this paper, we design a visually secure encryption scheme by using the parallel compressive sensing (PCS) counter mode and embedding technique. In order to achieve higher security level, Logistic-Tent system and 3-D Cat map are introduced to construct the measurement matrices and to disturb the order of the embedded information, respectively. Furthermore, experimental results demonstrate that the cipher image exhibits superior imperceptibility and the recovered image possesses more satisfactory quality, which is independent of the carrier image.