An adaptive quantum image encryption method based on wavelet transform is designed. Since the characteristic of most information is centralized in the low frequency part after performing the wavelet transform, it reserves the image low frequency information only, so as to reduce the encryption workload. Then it encrypts the low frequency information by the random key stream generated by logistic map, the encryption process is realized by implementing XOR operation. In the decryption process, it carries out zero filling operations for high frequency coefficient to recover the decryption images which are equal to the plain images. At the same time, the relevant quantum logical circuit is designed. Statistical simulation and theoretical analysis demonstrate that the proposed quantum image encryption algorithm has higher security and lower computational complexity. So it is adaptive to the scenes that need to encrypt a large number of images during network transmission.
An adaptive quantum image encryption method based on wavelet transform is designed. Since the characteristic of most information is centralized in the low frequency part after performing the wavelet transform, it reserves the image low frequency information only, so as to reduce the encryption workload. Then it encrypts the low frequency information by the random key stream generated by logistic map, the encryption process is realized by implementing XOR operation. In the decryption process, it carries out zero filling operations for high frequency coefficient to recover the decryption images which are equal to the plain images. At the same time, the relevant quantum logical circuit is designed. Statistical simulation and theoretical analysis demonstrate that the proposed quantum image encryption algorithm has higher security and lower computational complexity. So it is adaptive to the scenes that need to encrypt a large number of images during network transmission.
The quantum image encryption and authentication algorithm are proposed based on quantum affine transformation and quantum Haar wavelet transform. This algorithm is divided into two main steps: encryption and embedding. During the encryption phase, affine transform and Hénon map are combined to carry out scrambling-diffusion processing on the plaintext image. In the phase of embedding, the color carrier image undergoes decomposition using the quantum Haar wavelet transform. Then the ciphertext image information and identity information are hidden into the wavelet domain of the color carrier image, and the final transmitted image has visual significance. The suggested algorithm significantly minimizes the risk of image data compromise during transmission and realizes the dual security of encryption and authentication. The security and the robustness of the algorithm are analyzed by using the evaluation indexes of image encryption and information hiding. The findings indicate that the introduced algorithm offers superior security compared to alternative methods, ensuring a more dependable and safeguarded transmission of image data.
Given the limitations of current classic image encryption algorithms and the unconditional security characteristics of quantum key distribution protocols, the author proposes an image encryption method based on quantum key distribution and pixel scrambling. The author first analyzed the security issues of quantum image encryption algorithms based on image scrambling methods, namely that image scrambling methods have periodicity, which can ensure that the image can be restored after scrambling. If an image cannot be guaranteed to return to its original state after performing scrambling operations, legitimate users cannot obtain the secret information in the original image, and image scrambling loses its original meaning; However, the periodicity of image scrambling methods not only ensures that legitimate users can decrypt images, but also provides convenience for attackers to steal original image information. Secondly, it is pointed out that when evaluating and analyzing quantum image encryption algorithms, the evaluation indicators should include two parts: One is performance analysis, which is the analysis of the network complexity of quantum circuits. In quantum computing, the network complexity of quantum circuits is usually represented by the number of quantum basic logic gates. The second is security analysis, which mainly includes key analysis (including key space size and key sensitivity analysis), statistical analysis (including pixel correlation, histogram analysis, information fusion, and scatter plot distribution density analysis). Finally, experimental simulations have shown that the NPCR values of the plaintext and ciphertext images of the three images tend to 100%. The encrypted image histogram is evenly distributed, with very weak pixel correlation and high pixel change rate and information entropy.
An algorithm of quantum image encryption based on a normal arbitrary superposition state (NASS) is proposed by using quantum geometric transform, phase-shift transform, and quantum Haar wavelet packet transform (QHWPT) in this paper. Firstly, to scramble an image, we design an implementation circuit of quantum image pixel exchanges along diagonal lines. Next, [Formula: see text] keys randomly distributed between 0 and [Formula: see text] are encoded in the encryption algorithm by using phase-shift transform. The huge key space makes it difficult to attack encrypted images. Then, we store image information in low frequency using QHWPT to improve encryption effect. After that, the encryption algorithms of gray image and color image are simulated by using MATLAB, respectively. Meanwhile, evaluation indexes such as histogram, complexity and correlation of adjacent pixels are analyzed. Simulation experiments show that the proposed algorithm is valid.
In recent years, in the context of the rapid development of quantum computing technology, quantum attack methods such as Shor’s algorithm pose a serious threat to the traditional public key encryption system based on number-theoretic puzzles. Using the characteristics of quantum bits, this paper proposes a quantum grey-scale image encryption method based on alternating quantum random walk. Firstly, the quantum representation model is used to transform the image into a quantum state, and then the quantum key is generated by the alternating quantum random walk algorithm, and combined with the quantum gate operation for encrypting the grey-scale image data, which not only inherits the advantage of the anti-attack of the quantum computation, but also, through the quantum parallelism and the non-clonability, which solves the security and efficiency bottleneck of traditional image encryption in the quantum era and significantly improves the security of grey-scale image encryption. The algorithm proposed in this paper has been verified by simulation experiments, and the experimental results show that the method is excellent in encryption and decryption effects, and for the encrypted image, a number of performance analyses have been carried out, and the analysis results show that the proposed encryption method has a high degree of security, and it can effectively resist the statistical attack, noise attack, etc., and the distribution of the histogram of encrypted image is more uniform, the pixel correlation analysis is close to 1, and the information entropy is close to 7.999.
Abstract The parallel computing power of quantum computing and the special properties of qubits provide an effective solution for image processing tasks. This paper presents a quantum image encryption algorithm based on Fisher-Yates algorithm and Logistic mapping. Firstly, the Fisher-Yates algorithm is used to generate three key sequences, one of which is used to encode the coordinate qubits of the image. Using the other two keys and the preset rules, the quantum coordinate scrambling operation is designed based on the encoded coordinate qubit, which effectively scrambles the spatial information of the plaintext image. Next, another set of key sequences is generated, one of which is used to encode the color qubits of the image. Using two other key sequences and different rules, a qubit plane scrambling operation based on coded color qubits is designed, and the color information of image is scrambled successfully. Finally, the quantum key image is generated based on Logistic mapping, and the key image is scrambled based on Fisher-Yates algorithm to improve the key complexity. The final ciphertext image is obtained by performing XOR operation between the original image and the scrambled key image. The complete quantum circuit diagram of the scheme is given in this paper. The experimental results and security analysis prove the effectiveness of the scheme, which provides a large key space and the computational complexity is only O(n).
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.