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To trade security off for computational complexity, Selective Encryption (SE) in Image Processing denotes an approach which is capable of encrypting an image partially. In other words, it is aimed at turning the visually most important parts of images into meaningless ones, ignoring unimportant regions to have a computationally-efficient technique. Based on BRQI images, in this paper, a novel quantum selective encryption method for medical images is investigated. ROI (Region of Interest) tends to be the most vital part of medical images, which should be protected during the transmissions. The proposed method encrypts this region effectively by manipulating the bitplanes of the images according to a key. Experimental results encompassing correlation of adjacent pixels, histogram analysis and entropy rate analyzed in MATLAB environment demonstrate a good performance. Furthermore, regarding a BRQI image of 2n pixels, the time complexity is not more than O(m), where m is length of the key sequence. On no condition does it depend on size of images, bringing about being far more time-efficient compared to its classical counterpart and even earlier studied works found in the literature (full-encryption ones). To the best of our knowledge, this is the first method to introduce a quantum selective image encryption method. [ABSTRACT FROM AUTHOR]

The Kochen-Specker theorem is investigated for n spin-1/2 systems by using an inequality proposed in Nagata (J. Math. Phys. 46, 102101, 2005) on the basis on binary logic. A measurement theory based on the truth values (binary logic), i.e., the truth T (1) for true and the falsity F (0) for false is used. The values of measurement outcome are either + 1 or 0 (in ℏ / 2 unit). The quantum predictions by n-multipartite states violate the inequality by an amount that grows exponentially with n. The measurement theory based on the binary logic provides an exponentially stronger refutation of the existence of hidden-variable when the number of parties of the state increases more. It turns out that the Kochen-Specker theorem becomes a quite strong theorem when the dimension of the multipartite state highly increases, regardless of entanglement properties. [ABSTRACT FROM AUTHOR]

One of the most considering matters in the field of quantum information processing is quantum data hiding including quantum steganography and quantum watermarking. This field is an efficient tool for protecting any kind of digital data. In this paper, three quantum color images steganography algorithms are investigated based on Least Significant Bit (LSB). The first algorithm employs only one of the image's channels to cover secret data. The second procedure is based on LSB XORing technique, and the last algorithm utilizes two channels to cover the color image for hiding secret quantum data. The performances of the proposed schemes are analyzed by using software simulations in MATLAB environment. The analysis of PSNR, BER and Histogram graphs indicate that the presented schemes exhibit acceptable performances and also theoretical analysis demonstrates that the networks complexity of the approaches scales squarely. [ABSTRACT FROM AUTHOR]

Watermarking is the imperceptible embedding of watermark bits into multimedia data in order to use for different applications. Among all its applications, copyright protection is the most prominent usage which conceals information about the owner in the carrier, so as to prohibit others from assertion copyright. This application requires high level of robustness. In this paper, a new blind quantum copyright protection method based on owners's signature in RGB images is proposed. The method utilizes one of the RGB channels as indicator and two remained channels are used for embedding information about the owner. In our contribution the owner's signature is considered as a text. Therefore, in order to embed in colored image as watermark, a new quantum representation of text based on ASCII character set is offered. Experimental results which are analyzed in MATLAB environment, exhibit that the presented scheme shows good performance against attacks and can be used to find out who the real owner is. Finally, the discussed quantum copyright protection method is compared with a related work that our analysis confirm that the presented scheme is more secure and applicable than the previous ones currently found in the literature. [ABSTRACT FROM AUTHOR]

Quantum watermarking is utilized to embed specific information, usually the owner's identification, into quantum multimedia data such as audio, video and image, mainly for copyright protection purposes. In the present contribution, a new watermark strategy for quantum images is proposed. In this scheme and with the aim of data hiding, in addition to using the least significant bit (LSB), the most significant bit (MSB) is also employed. Software simulation and the peak-signal-to-noise ratio (PSNR) calculation confirm that the presented scheme is more secure and applicable than the previous ones currently found in the literature. [ABSTRACT FROM AUTHOR]

Skeletonization or thinning process is an important step in pre-processing phase and it is crucial process for many applications such as pattern recognition, data compression/storage, OCR, etc. In classical information, there are several algorithms proposed for the aim of image skeletonization or thinning. One of the widely used algorithm for this purpose is Hilditch's algorithm. In this paper a novel quantum version of Hilditch's algorithm for quantum image thinning is proposed where the novel enhanced quantum representation of digital images (NEQR model) is employed for representation of the quantum images. The proposed algorithm can be considered as the first quantum image thinning algorithm used in any schemes proposed in the growing field of quantum image processing. [ABSTRACT FROM AUTHOR]

Quantum watermarking is a technique which embeds the invisible quantum signal such as the owners identification into quantum multimedia data (such as audio, video and image) for copyright protection. In this paper, using a quantum representation of digital images a new quantum watermarking protocol including quantum image scrambling based on Least Significant Bit (LSB) is proposed. In this protocol, by using m-bit embedding key K and m-bit extracting key K a m-pixel gray scale image is watermarked in a m-pixel carrier image by the original owner of the carrier image. For validation of the presented scheme the peak-signal-to-noise ratio (PSNR) and histogram graphs of the images are analyzed. [ABSTRACT FROM AUTHOR]

An image histogram diagram illustrates the frequency of intensity values occurring in an image. A histogram figure has two dimensions including the x-axis and the y-axis. The color values are demonstrated by the former, and the latter indicates the number of pixels having the corresponding color values. Because quantum image processing (QImP) has been developed rapidly in recent years, in this paper, a new general approach to construct quantum image histogram (QIH) for quantum grayscale and RGB images is proposed, which is based on two kinds of quantum images named novel enhanced quantum representation of digital images (NEQR) and novel colored quantum images (NCQI). QIH manipulates two entangled qubit sequences with the aim of storing and preparing image histogram information, constructing a quantum model for illustrating image histogram. This model requires (q + 2 n + 1) qubits based on NEQR image and 3 × (q + 2 n + 1) qubits based on RGB image to construct the image histogram, when size of image is 2 n × 2 n with gray (color) range 2 q . Moreover, our constructive polynomial preparation proves that the time complexity of QIH is not more than O (n q 2 2 n + q) . To the best of our knowledge, this is the first general approach for encoding histogram information based on quantum RGB and grayscale images, and it may open a new window to further statistical analysis procedures related to QImP. For instance, a practical use of QIH as a strict criterion to evaluate quantum data hiding algorithms is also discussed in this paper. [ABSTRACT FROM AUTHOR]

Considering blindness in information security, image scrambling method is defined as a procedure by which an image is turned into an absolutely different meaningless image through a reversible transformation. By scrambling an image, the ability to resist against unauthorized attacks and accordingly, augmenting security can be obtained effectively. In this approach, a quantum representation of a digital scrambling algorithm is investigated for quantum NCQI color images. Experimental consequences encompassing histogram diagram, entropy rate, correlation coefficient and number of pixels change ratio, which are analyzed in MATLAB environment, indicate a good performance, showing that the proposed method is much more secure and applicable than the previous one currently found in the literature related to the quantum image disordering methods. [ABSTRACT FROM AUTHOR]

Here, we discuss the generalized Bernstein-Vazirani algorithm for determining a complex number string. The generalized algorithm presented here has the following structure. Given the set of complex values {a1, a2, a3,..., aN} and a special function g : C → C , we determine N real parts of values of the function l(a1), l(a2), l(a3),..., l(aN) and N imaginary parts of values of the function h(a1), h(a2), h(a3),..., h(aN) simultaneously. That is, we determine the N complex values g(aj) = l(aj) + ih(aj) simultaneously. We mention the two computing can be done in parallel computation method simultaneously. The speed of determining the string of complex values is shown to outperform the best classical case by a factor of N. Additionally, we propose a method for calculating many different matrices A, B, C,... into g(A), g(B), g(C),... simultaneously. The speed of solving the problem is shown to outperform the classical case by a factor of the number of the elements of them. We hope our discussions will give a first step to the quantum simulation problem. [ABSTRACT FROM AUTHOR]