This paper proposes an encryption scheme, where bit-XOR operation between the rows of quantum polarization angles 0°, 45°, 90°, 135° and a key generated by quantum polarization angles is done. Then the bit-XORed rows are swapped from 0°to 45°and 90° to 135°. Then the image is divided into four blocks and bit-XOR operation is performed between each tile and a key generated using quantum polarization angles. Then the tiles are concatenated to form an image. The resultant image is encrypted by random permutation and bit-XOR operation is performed with randomly generated key to form the final encrypted image.
This paper proposes an encryption scheme, where bit-XOR operation between the rows of quantum polarization angles 0°, 45°, 90°, 135° and a key generated by quantum polarization angles is done. Then the bit-XORed rows are swapped from 0°to 45°and 90° to 135°. Then the image is divided into four blocks and bit-XOR operation is performed between each tile and a key generated using quantum polarization angles. Then the tiles are concatenated to form an image. The resultant image is encrypted by random permutation and bit-XOR operation is performed with randomly generated key to form the final encrypted image.
In this paper, a quantum image encryption scheme is proposed by using the inter–intra bit-level permutation strategy. The image to be encrypted is first represented by a novel enhanced quantum representation model, and then, the intra and inter permutation operations are successively performed on bit planes. The intra bit permutation is achieved by sorting chaotic sequence, and the inter bit permutation is accomplished with qubit XOR operations between the two selected bit planes. The ciphertext image is finally obtained through a chaotic diffusion procedure implemented with a quantum image XOR operation. The XOR operation is realized by controlled- NOT gates, which is controlled by a chaotic sequence generated with a logistic map. The parameters of the logistic map are sensitive, which makes the key space large enough to resist brute-force attack. The proposed scheme not only modifies the pixel positions and gray values but also makes the bit distribution more uniform. The quantum circuits for the proposed encryption algorithm are devised. The simulation results and theoretical analysis show that the proposed method is more efficient than its classical counterpart, and its security is verified by the statistical analysis, keys sensitivity, and key space analysis.
Background: The growth in the field of communication has enabled the people at miles apart to communicate easily.Once the online sharing of information is made possible.It is necessary to ensure about the security of the information that is shared.Materials and Methods: In this study, three levels of encryption process has been carried out.Quantum Key Distribution(QKD) with bit XOR forms the first level of encryption.Flipping and swapping of the ciphered block images were done using quantum walk principle forms the second and the third level of encryption.Results and Discussion: To prove the robustness of the proposed scheme, image encryption metrices like horizontal, vertical, diagonal correlations, No. of Pixel Change Rate (NPCR), Unified Average Changing Intensity(UACI) were estimated and compared with the available literature.Conclusion: The QKD and quantum walks forms the basic level of image encryption and offers NPCR 99.68 and UACI of 30.50.Flipping, swapping and bit XOR of the ciphered block images were done.To verify the robustness of the proposed method and the values are found to be better.
In view of the limitations of existing image encryption technique and high security of quantum key distribution scheme, an image encryption algorithm based on six-state quantum key distribution scheme is proposed. On the basis of two groups of conjugate bases of four states scheme(BB84 protocol), another pair of rotating measuring bases are introduced to constitute six state base space; random binary key strings are generated with six-state scheme, then the key strings and image data are operated with XOR, and image data are replaced with the operation results. Experimental results and security analysis show that with the new algorithm key space increased, the brute force attack can be resisted; with lower relevancy of plaintext and cipher text, the chosenplaintext attack can be effectively resisted; the algorithm achieves better sensitivity and security.
Background: Quantum image processing is rapidly developing in the field of quantum computing, and it can be successfully implemented on the Noisy Intermediate-Scale Quantum (NISQ) device. Quantum image encryption holds a pivotal position in this domain. However, the encryption process often encounters security vulnerabilities and entails complex computational complexities, thereby consuming substantial quantum resources. To address this, the present study proposes a quantum image encryption algorithm based on four-dimensional chaos. Methods: The classical image is first encoded into quantum information using the Generalized Quantum Image Representation (GQIR) method. Subsequently, the trajectory of the four-dimensional chaotic system is randomized, and multi-dimensional chaotic keys are generated to initially encrypt the pixel values of the image. Then, the Arnold transformation is applied to randomly encrypt the pixel positions, resulting in the encrypted image. During the decryption process, the inverse process of encryption is employed to restore the original image. Results: We simulated this process in the Python environment, and the information entropy analysis experiment showed that the information entropy of the three encrypted images reached above 7.999, so the system has good encryption. At the same time, the correlation of the pixel distribution after the encryption algorithm is weak, which proves that the control parameters of the chaotic system can effectively reduce the correlation between pixels in the image. In the final key space analysis, the key space issued by our encryption can reach $10 140 \gg 2 128 $. Conclusion: Our method is resistant to destructive attacks and can produce scrambled images with higher encryption and usability. This algorithm solves the problems of general encryption algorithms such as periodicity, small key space, and vulnerability to statistical analysis, and proposes a reliable and effective encryption scheme. By making full use of the characteristics of Arnold transformation permutation, ergodicity and the randomness of the four-dimensional chaotic system, the encryption algorithm uses the larger key space provided by the four-dimensional Lorenz system.
A quantum color image encryption algorithm based on geometric transformation and intensity channel diffusion was designed. Firstly, a plaintext image was transformed into a quantum state form using the quantum image representation based on HSI color space (QIRHSI) representation as a carrier. Next, a pseudo-random sequence was generated using the generalized logistic map, and the pixel positions permuted multiple two-point swap operations. Immediately afterward, the intensity values were changed by an intensity bit-plane cross-swap and XOR, XNOR operations. Finally, the intensity channel of the above image was diffused in combination with the pseudo-confusion sequence as produced by the quantum logistic map to perform a diffusion operation on the intensity bit-plane to obtain the ciphertext image. Numerical simulations and analyses show that the designed algorithm is implementable and robust, especially in terms of outstanding performance and less computational complexity than classical algorithms in terms of security perspective.
Quantum image encryption is an emerging technology for efficiently protecting visual information. A quantum block image encryption scheme is designed based on quantum Arnold transform (QArT) and lately proposed sine chaotification model (SCM) in this paper. First, in order to flexibly manipulate image blocks, a quantum block image representation (QBIR) model for block image is proposed, which encodes pixel gray values and position information of image blocks into two entangled qubit sequences. Then, QArT is applied to scramble the positions of image blocks. The final ciphertext image is obtained by quantum XOR operations, which is completed with a pseudorandom sequence generated from SCM. The introduction of SCM dramatically enlarges the key space to resist brute-force attack. Moreover, the generated sequence is dependent on the original image to resist the chosen-plaintext attack. The main quantum circuits are given and the numerical simulation results demonstrate that the proposed quantum image encryption scheme is valid and reliable for quantum image protection in terms of security and computational complexity.