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411.
In practical optical security systems we must consider various circumstances for reading and decrypting encrypted holograms.
Binarization of the hologram is best suited for such applications because of the ease of handling encrypted data. However,
the decrypted image is greatly degraded by binarization. Therefore, optimization of a binary hologram is essential in using
such a technique. In this paper, we propose a fast optimization method of a binary encrypted hologram to obtain a good reconstruction
based on the error correction algorithm. In the proposed method, multiple pixels of the binary hologram are simultaneously
flipped for the optimization according to the priority for the correction. The time for the optimization is only 3% of that
of the simulated annealing method. 相似文献
412.
By combining quantum key with classical one, a novel block cryptographic algorithm that can be applied to encrypt qubits is presented. The security of the algorithm is analyzed from several aspects. It is shown that the qubit block encryption algorithm can prevent quantum attacking strategy as well as classical attacking strategy. The hybrid keys are securely reusable after a checking process, which lessens the task of key management significantly. The proposed algorithm offers an alternative to the standard one-time-pad encryption of a quantum bit string using a quantum key. 相似文献
413.
一种光电器件加密方法的安全性分析 总被引:1,自引:1,他引:0
为了找到一种安全、高速的图像加密方法,通过计算明文和密文的信息熵、灰度值等参数,研究了利用光电器件,采用流密码和位平面分解相结合的加密方法的安全性和该方案的抗破译能力。结果表明,该方案中, 对含信息量越少的图像,加密后平均灰度变化值越大;这种灰度变换的加密方法掩盖了各像素点之间的相关性,密文像素点灰度随机分布,分析者无法获得明文图像的灰度分布状况,使得分析者无法通过相关度分析提取图像轮廓,有效隐藏重要信息。因此,该加密方法具有极高的安全性,同时应将密文平均灰度值作为评价参数之一。 相似文献
414.
A broadcast on a graph G is a function f:V→Z+∪{0}. The broadcast number of G is the minimum value of ∑v∈Vf(v) among all broadcasts f for which each vertex of G is within distance f(v) from some vertex v with f(v)≥1. This number is bounded above by the radius and the domination number of G. We show that to characterize trees with equal broadcast and domination numbers it is sufficient to characterize trees for which all three of these parameters coincide. 相似文献
415.
本文安全分析文献 所提的一类自同步的时空混沌流密码系统.发现该高维的加解密系统在常数的驱动下将收敛到一维,使得动力学系统的复杂性大为降低.在某些特定输入区域内容,保密系统对输入状态的微小扰动不敏感.可以建立密钥和特殊输入状态间一个简单的线性关系,并依次从密钥流中恢复出密钥.基于此,提出一套选择密文攻击方法,利用系统参数和扰动前后密钥流的差异之间的依赖关系通过寻优算法破解密钥,从而攻击了上述文献所提出的基于混沌自同步的安全通信算法.
关键词:
混沌密码
耦合映像格子
安全分析 相似文献
416.
A novel image encryption method based on total shuffling scheme 总被引:4,自引:0,他引:4
Guoji Zhang 《Optics Communications》2011,284(12):2775-37
In this paper, a novel image encryption method based on skew tent chaotic map and permutation-diffusion architecture is proposed. In the proposed method, the P-box is chosen as the same size of plain-image, which shuffles the positions of pixels totally. The keystream generated by skew tent chaotic map is related to the plain-image. Statistical analysis, information entropy analysis, and sensitivity analysis to plaintext and key on the proposed scheme are provided in this paper. It can be seen that this algorithm is efficient and reliable, with high potential to be adopted for network security and secure communications. 相似文献
417.
Ruisong Ye 《Optics Communications》2011,284(22):5290-5298
This paper proposes a novel chaos-based image encryption scheme with an efficient permutation-diffusion mechanism, in which permuting the positions of image pixels incorporates with changing the gray values of image pixels to confuse the relationship between cipher-image and plain-image. In the permutation process, a generalized Arnold map is utilized to generate one chaotic orbit used to get two index order sequences for the permutation of image pixel positions; in the diffusion process, a generalized Arnold map and a generalized Bernoulli shift map are employed to yield two pseudo-random gray value sequences for a two-way diffusion of gray values. The yielded gray value sequences are not only sensitive to the control parameters and initial conditions of the considered chaotic maps, but also strongly depend on the plain-image processed, therefore the proposed scheme can resist statistical attack, differential attack, known-plaintext as well as chosen-plaintext attack. Experimental results are carried out with detailed analysis to demonstrate that the proposed image encryption scheme possesses large key space to resist brute-force attack as well. 相似文献
418.
Xiaopeng Yan 《中国物理 B》2022,31(8):80504-080504
We present a new cosine chaotic mapping proved by chaos theory test and analysis such that the system has good cryptography properties, wide chaos range, simple structure, and good sensitivity to initial value, and the mapping can meet the needs of chaotic image encryption. Based on the cosine chaotic system, we propose a new encryption method. First, according to the cyclic characteristics of the mapping, the cyclic information wave is simulated. Second, the quasi-Doppler effect is used to synchronously scramble and diffuse the image to obfuscate the original pixel. Finally, the XOR diffusion of image pixels is carried out by information wave to further enhance the encryption effect. Simulation experiment and security analysis show that the algorithm has good security, can resist the common attack mode, and has good efficiency. 相似文献
419.
Xiao-Gang Wang 《中国物理 B》2022,31(9):94202-094202
The two types of nonlinear optical cryptosystems (NOCs) that are respectively based on amplitude-phase retrieval algorithm (APRA) and phase retrieval algorithm (PRA) have attracted a lot of attention due to their unique mechanism of encryption process and remarkable ability to resist common attacks. In this paper, the securities of the two types of NOCs are evaluated by using a deep-learning (DL) method, where an end-to-end densely connected convolutional network (DenseNet) model for cryptanalysis is developed. The proposed DL-based method is able to retrieve unknown plaintexts from the given ciphertexts by using the trained DenseNet model without prior knowledge of any public or private key. The results of numerical experiments with the DenseNet model clearly demonstrate the validity and good performance of the proposed the DL-based attack on NOCs. 相似文献
420.
Finite-time complex projective synchronization of fractional-order complex-valued uncertain multi-link network and its image encryption application
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Yong-Bing Hu 《中国物理 B》2022,31(11):110501-110501
Multi-link networks are universal in the real world such as relationship networks, transportation networks, and communication networks. It is significant to investigate the synchronization of the network with multi-link. In this paper, considering the complex network with uncertain parameters, new adaptive controller and update laws are proposed to ensure that complex-valued multilink network realizes finite-time complex projective synchronization (FTCPS). In addition, based on fractional-order Lyapunov functional method and finite-time stability theory, the criteria of FTCPS are derived and synchronization time is given which is associated with fractional order and control parameters. Meanwhile, numerical example is given to verify the validity of proposed finite-time complex projection strategy and analyze the relationship between synchronization time and fractional order and control parameters. Finally, the network is applied to image encryption, and the security analysis is carried out to verify the correctness of this method. 相似文献