Visual Security Research Articles

A Digital Hologram Encryption Method Using Data Scrambling of Frequency Coefficients

A digital hologram generated by a computer calculation (computer-generated hologram or capture using charge-coupled device [CCD] camera) is one of the most expensive types of content, and its usage is expanding. Thus, it is highly necessary to protect the ownership of digital holograms. This paper presents an efficient visual security scheme for holographic image reconstruction with a low scrambling cost. Most recent studies on optical security concentrate their focus on security authentication using optical characteristics. However, in this paper, we propose an efficient scrambling method to protect a digital hologram. Therefore, we introduce in this paper several scrambling attempts in both the spatial domain and frequency domain on the basis of the results of analyzing the properties of the coefficients in each domain. To effectively hide the image information, 1/4, 1/256, and 1/16,384 of the original digital hologram needs to be scrambled for the spatial-domain scheme, Fresnel-domain scheme, and discrete cosine transform-domain scheme, respectively. The encryption schemes and the analyses in this paper can be expected to be useful in the research on encryption and other works on digital holograms.

Enhancing the Specular Effect of Metallic Color Prints by Reducing the Use of Yellow Ink

The MetallicArt technique is used as a visual security feature to hide patterns in CMY images using an additional silver ink. The patterns are hidden under nonspecular viewing conditions and visible under specular viewing conditions. By varying the amount of silver ink, the authors control the intensity of the specular reflection of the printed pattern. Using a spectral reflection prediction model, they can constrain the maximization of the silver ink (S) in order to keep the color difference between the original CMY color and the fitted CMYS color under a given threshold, ensuring that the pattern is hidden under nonspecular viewing conditions. When the printing device requires the inks to be UV cured, the leafing effect of the silver ink is reduced. This also reduces the specular reflection of the silver ink, which becomes comparable to the specular reflection of the yellow ink. Since both specular reflections are similar, it is difficult to distinguish the embedded patterns under specular viewing conditions when both inks are present. The authors, therefore, propose a new algorithm to embed patterns in CMY images that not only maximizes silver but also minimizes yellow. Experimental results show that the proposed algorithm enhances the visibility of the patterns under specular viewing conditions, allowing the use of MetallicArt when the printing device requires UV curing. (C) 2011 Society for Imaging Science and Technology [DOI: 10.2352/J.ImagingSci.Technol.2011.55.6.060506]

Visual data security and management for smart cities

This paper proposes a method to manage and utilize image and video data effectively in a smart city. Applying digital watermarking techniques, a framework for visual data security and management for smart cities is presented. In the framework, a reversible fragile or semi-fragile watermark embedded into the visual data is used to ensure trusted acquisition. Moreover, reversible metadata watermarks carrying information such as identification and other properties data is used to assist visual data management. A solution for tracing users on a large scale is presented using reversible watermarking.

An objective visual security assessment for cipher-images based on local entropy

In recent years, many practical algorithms have been put forward for images and videos encryption. Security analysis on these encryption algorithms focuses research on cryptographic security, and few work relate to visual security. Visual security means that the encrypted video content is unintelligible to human vision. The higher visual security the encryption algorithm can provide, the less information an attacker from the cipher-images to obtain, the greater the difficulty of attack is. Therefore, visual security assessment for cipher-images is a very important indicator in security evaluation of visual media. So far, systematic research on visual security assessment for cipher-images is far from enough. Moreover, there are no practical objective indicators or evaluation methods on visual security have been proposed at present. According to the changes on image information entropy between cipher-images and original images, we present a visual security assessment algorithm based on local entropy. The experiments result shows that the scheme can provide an efficient objective assessment which is match up to subjective assessment, and is also suitable for security assessment of other selective encryption algorithms.

Evaluation on tourism ecological security in nature heritage sites —Case of Kanas nature reserve of Xinjiang, China

The nature heritages are the precious legacy of nature with outstanding scientific and aesthetic value. They are quite different from other common ecotourism areas, because of its original and unique system, sensitive and vulnerable landscape, and peripheral cultural features. Therefore, the tourism development in the nature heritage sites should be on the premise of ecological security. The evaluation index system of tourism ecological security in nature heritage sites was constructed in this article by AHP and Delphi methods, including nature ecological security, landscape visual security and local culture ecological security, and the security thresholds of indices were also established. In the indices’ weights of the evaluation model, the nature ecological security ranked the highest, followed by tourist landscape visual security and culture ecological security, which reflected the influence degree of the limited factor to tourism ecological security. Then, this paper carried out an empirical study of Kanas of Xinjiang Uygur Autonomous Region, China, which has the potential to be the World Nature Heritage. On the basis of the data attained from survey and observation on the spot, as well as questionnaire answered by tourists and local communities, the ecological security status in Kanas was evaluated. The result showed that the status of Kanas tourism ecological security was better, but there had some limiting factors. Lastly, effective measures were put forward to ensure its ecological security.

Identification of Counterfeit Drugs by Community Pharmacists in Lagos State

Purpose: The problem of fake and counterfeit drugs is real and constitutes a major threat to the health and safety of the Nigerian population. A descriptive study was carried out to assess the methods of identification of counterfeit drugs by community pharmacists in Lagos State. Methods: The research instrument was a 23-item questionnaire, which was administered to consenting community pharmacists in 17 out of the 20 Local Government Areas in Lagos State. A convenient sample of practicing community pharmacists both in retail and wholesale distribution of pharmaceutical products were recruited into the study using a list of registered pharmacists from the Association of Community Pharmacists in Lagos State. Effort was made to ensure adequate representation of Pharmacies in every local government area in Lagos State. Results: All the respondents agreed that there is a fake and counterfeit drug problem in Nigeria, and (74%) considered this a major problem. The respondents commonly used visual security techniques before drug purchasing. These were: Seals/embossments (83%), character of print (77%), and Holograms (68%).The respondents' most likely action after a counterfeit drug encounter was to return the drug back to the supplier. Conclusion: The study showed that pharmacists sampled were aware of the prevalence of fake and counterfeit drugs and quite a number of them have had encounters with them. There is an indication that the respondents try to assure themselves of the quality of the drugs they purchase by use of several methods. However, no rigorous effort was taken to confirm as well as report suspected fake and counterfeit drugs to regulatory authorities. Keywords: Community pharmacists, drug identification, fake and counterfeit drugs. > Tropical Journal of Pharmaceutical Research Vol. 5 (1) 2006: pp. 545-550

Corporate wireless LAN security: threats and an effective security assessment framework for wireless information assurance

In this paper, we propose the necessary steps in implementing strong WLAN security for companies using our visual security assessment framework for wireless information assurance. Through real case studies on the organisations with various security measures and by showing complete execution paths of our framework, we suggest the importance of continual assessment of the WLAN for strong corporate security assurance using our Corporate WLAN Security Assessment Framework.

Visual authorization modeling in e-commerce applications

Considers how task-based security models let enterprises control access at the application rather than the operating system level. The Visual Security Administrator (Visa) uses visual languages to represent steps in this authorization process with icons and gestures to support security management by nontechnical users, such as enterprise managers.

Gratings of constantly varying depth for visual security devices

Sinusoidal gratings of locally varying profile depth are incor- porated into diffractive optically variable image devices (DOVIDs) for document security. The variation in profile depth is tailored to specific visual effects that can be readily authenticated. While the diffractive characteristics of these gratings depend very sensitively on the depth, the security of these DOVIDs is inherent to the diffractive structures insofar as the exact reconstruction of the original profile is required for the realization of the original visual effects. Sinusoidal gratings of locally varying profile depth are very resistant against copying by standard ho- lographic techniques since these techniques are shown to lead to a loss of fidelity in profile form or depth. © 1999 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(99)00101-4)

IBS '83

Britain's largest and most comprehensive exhibition of office equipment and services, the International Business Show, throws wide its doors at the National Exhibition Centre in Birmingham on October 18th. The Rt Hon David Steel MP is to open the show and the organisers, BETA Exhibitions Ltd, have arranged with the Institute of Directors to stage a one‐day conference on “Computer Aided Business; how to beat the competition and win new customers”. A multitude of offerings will be on display covering everything from stationery, filing systems and furniture to audio visual aids, microfilm, computers, inter‐communication and security systems. Everything, in fact, that the modern business could conceivably require.