Biblio

The paper presents a cryptanalysis of an enhanced sub-image encryption method recently proposed by Wang et al. in Optics and Lasers in Engineering 86(2016). Their paper shows that a parallel sub-image encryption method proposed by Mirzaei et al. in Nonlinear Dyn. 67(2012) could be attacked by chosen plaintext attack and proposed an enhanced sub-image encryption method claimed to completely resist the chosen plaintext attack. However, the enhanced sub-image encryption method also has some weakness, such as the key streams are independent with the plain-image. In this paper, one chosen plaintext attack type of cryptanalysis is presented for the enhanced sub-image encryption method and completely broken the enhanced sub-image encryption method. The experimental results indicate that the enhanced sub-image encryption method is weak against chosen plaintext attack and should be improved for practical application.

In this paper, a novel chaotic image encryption scheme based on the inverse fractal interpolation function system is proposed. The inverse fractal interpolation function system associated with fractal interpolation surface is applied to generate chaotic sequences. The derived sequences are then employed to permute the pixel positions to get the shuffled image by chaotic sequence sorting. The obtained chaotic sequences are then quantized to yield one pseudo-random gray value sequence used to perform diffusion to enhance the security. The security and performance of the proposed image encryption scheme have been analysed, including histograms, correlation coefficients, information entropy, differential analysis, etc. All the experimental results suggest that the proposed image encryption scheme is robust and secure and can be used for secure image and video communication applications.

In this paper, a new image encryption algorithm is presented with one chaotic map and one group of secret keys. Double permutations for pixel positions are designed followed by a function of diffusion to alter gray distribution in the plain-image. In the proposed algorithm, the keystream is produced and dependent on the plain-image. As a result, the method can frustrate the known plaintext attack and chosen plaintext attack. Moreover, diffusion encryption by row-only is applied to the permuted image to save time consumption. Then, the experimental results show that our method can perform high security and is suitable for both gray and color images.

In the literature, many chaotic systems have been used in the design of image encryption algorithms. In this study, an application of fractional order chaotic systems is investigated. The aim of the study is to improve the disadvantageous aspects of existing methods based on discrete and continuous time chaotic systems by utilizing the features of fractional order chaotic systems. The most important advantage of the study compared to the literature is that the proposed encryption algorithm is designed with a provable security approach. Analyses results have been shown that the proposed method can be used successfully in many information security applications.

Cryptography is a widespread technique that maintains information security over insecure networks. The symmetric encryption scheme provides a good security, but the key exchange is difficult on the other hand, in the asymmetric encryption scheme, key management is easier, but it does not offer the same degree of security compared to symmetric scheme. A hybrid cryptosystem merges the easiness of the asymmetric schemes key distribution and the high security of symmetric schemes. In the proposed hybrid cryptosystem, Serpent algorithm is used as a data encapsulation scheme and Elliptic Curve Cryptography (ECC) is used as a key encapsulation scheme to achieve key generation and distribution within an insecure channel. This modification is done to tackle the issue of key management for Serpent algorithm, so it can be securely used in multimedia protection.

Applying security to the transmitted image is very important issues, because the transmission channel is open and can be compromised by attackers. To secure this channel from the eavesdropping attack, man in the middle attack, and so on. A new hybrid encryption image mechanism that utilize triangular scrambling, DNA encoding and chaotic map is implemented. The scheme takes a master key with a length of 320 bit, and produces a group of sub-keys with two length (32 and 128 bit) to encrypt the blocks of images, then a new triangular scrambling method is used to increase the security of the image. Many experiments are implemented using several different images. The analysis results for these experiments show that the security obtained on by using the proposed method is very suitable for securing the transmitted images. The current work has been compared with other works and the result of comparison shows that the current work is very strong against attacks.

In this paper, we introduce a fast, secure and robust scheme for digital image encryption using chaotic system of Lorenz, 4D hyper-chaotic system and the Secure Hash Algorithm SHA-1. The encryption process consists of three layers: sub-vectors confusion and two-diffusion process. In the first layer we divide the plainimage into sub-vectors then, the position of each one is changed using the chaotic index sequence generated with chaotic attractor of Lorenz, while the diffusion layers use hyper-chaotic system to modify the values of pixels using an XOR operation. The results of security analysis such as statistical tests, differential attacks, key space, key sensitivity, entropy information and the running time are illustrated and compared to recent encryption schemes where the highest security level and speed are improved.

Image encryption takes been used by armies and governments to help top-secret communication. Nowadays, this one is frequently used for guarding info among various civilian systems. To perform secure image encryption by means of various chaotic maps, in such system a legal party may perhaps decrypt the image with the support of encryption key. This reversible chaotic encryption technique makes use of Arnold's cat map, in which pixel shuffling offers mystifying the image pixels based on the number of iterations decided by the authorized image owner. This is followed by other chaotic encryption techniques such as Logistic map and Tent map, which ensures secure image encryption. The simulation result shows the planned system achieves better NPCR, UACI, MSE and PSNR respectively.

This paper proposes a new hybrid technique for combined encryption text and image based on hyperchaos system. Since antiquity, man has continued looking for ways to send messages to his correspondents in order to communicate with them safely. It needed, through successive epochs, both physical and intellectual efforts in order to find an effective and appropriate communication technique. On another note, there is a behavior between the rigid regularity and randomness. This behavior is called chaos. In fact, it is a new field of investigation that is opened along with a new understanding of the frequently misunderstood long effects. The chaotic cryptography is thus born by inclusion of chaos in encryption algorithms. This article is in this particular context. Its objective is to create and implement an encryption algorithm based on a hyperchaotic system. This algorithm is composed of four methods: two for encrypting images and two for encrypting texts. The user chose the type of the input of the encryption (image or text) and as well as of the output. This new algorithm is considered a renovation in the science of cryptology, with the hybrid methods. This research opened a new features.

Aerial photography is fast becoming essential in scientific research that requires multi-agent system in several perspective and we proposed a secured system using one of the well-known public key cryptosystem namely NTRU that is somewhat homomorphic in nature. Here we processed images of aerial photography that were captured by multi-agents. The agents encrypt the images and upload those in the cloud server that is untrusted. Cloud computing is a buzzword in modern era and public cloud is being used by people everywhere for its shared, on-demand nature. Cloud Environment faces a lot of security and privacy issues that needs to be solved. This paper focuses on how to use cloud so effectively that there remains no possibility of data or computation breaches from the cloud server itself as it is prone to the attack of treachery in different ways. The cloud server computes on the encrypted data without knowing the contents of the images. After concatenation, encrypted result is delivered to the concerned authority where it is decrypted retaining its originality. We set up our experiment in Amazon EC2 cloud server where several instances were the agents and an instance acted as the server. We varied several parameters so that we could minimize encryption time. After experimentation we produced our desired result within feasible time sustaining the image quality. This work ensures data security in public cloud that was our main concern.

Discrete Cosine Transform (DCT) is used in JPEG compression, image encryption, image watermarking and channel estimation. In this paper, an Application Specific Processor (ASP) for DCT based applications is designed and implemented to Field Programmable Gate Array (FPGA). One dimensional DCT and IDCT hardwares which have fully parallel architecture have been implemented and connected to MicroBlaze softcore processer. To show a basic application of ASP, DCT based image watermarking example is studied in this system.

This paper proposes a novel plan of compacting encoded pictures with helper data. The substance manager scrambles the first uncompressed pictures furthermore creates some helper data, which will be utilized for information pressure and picture recreation. At that point, the channel supplier who can't get to the first substance may pack the encoded information by a quantization technique with ideal parameters that are gotten from a piece of helper data and a pressure proportion mutilation criteria, and transmit the packed information, which incorporate a scrambled sub-picture, the quantized information, the quantization parameters and an alternate piece of assistant data. At recipient side, the key picture substance can be reproduced utilizing the packed scrambled information and the mystery key.

A novel secure arithmetic image coding algorithm based on Two-dimensional Generalized Logistic Mapping is proposed. Firstly, according to the digital image size m×n, two 2D chaotic sequences are generated by logistic chaotic mapping. Then, the original image data is scrambled by sorting the chaotic sequence. Secondly, the chaotic sequence is optimized to generate key stream which is used to mask the image data. Finally, to generate the final output, the coding interval order is controlled by the chaotic sequence during the arithmetic coding process. Experiment results show the proposed secure algorithm has good robustness and can be applied in the arithmetic coder for multimedia such as video and audio with little loss of coding efficiency.

In our digital world internet is a widespread channel for transmission of information. Information that is transmitted can be in form of messages, images, audios and videos. Due to this escalating use of digital data exchange cryptography and network security has now become very important in modern digital communication network. Cryptography is a method of storing and transmitting data in a particular form so that only those for whom it is intended can read and process it. The term cryptography is most often associated with scrambling plaintext into ciphertext. This process is called as encryption. Today in industrial processes images are very frequently used, so it has become essential for us to protect the confidential image data from unauthorized access. In this paper Advanced Encryption Standard (AES) which is a symmetric algorithm is used for encryption and decryption of image. Performance of Advanced Encryption Standard algorithm is further enhanced by adding a key stream generator W7. NIOS II soft core processor is used for implementation of encryption and decryption algorithm. A system is designed with the help of SOPC (System on programmable chip) builder tool which is available in QUARTUS II (Version 10.1) environment using NIOS II soft core processor. Developed single core system is implemented using Altera DE2 FPGA board (Cyclone II EP2C35F672). Using MATLAB the image is read and then by using DWT (Discrete Wavelet Transform) the image is compressed. The image obtained after compression is now given as input to proposed AES encryption algorithm. The output of encryption algorithm is given as input to decryption algorithm in order to get back the original image. The implementation of which is done on the developed single core platform using NIOS II processor. Finally the output is analyzed in MATLAB by plotting histogram of original and encrypted image.

We propose an optical security method for object authentication using photon-counting encryption implemented with phase encoded QR codes. By combining the full phase double-random-phase encryption with photon-counting imaging method and applying an iterative Huffman coding technique, we are able to encrypt and compress an image containing primary information about the object. This data can then be stored inside of an optically phase encoded QR code for robust read out, decryption, and authentication. The optically encoded QR code is verified by examining the speckle signature of the optical masks using statistical analysis. Optical experimental results are presented to demonstrate the performance of the system. In addition, experiments with a commercial Smartphone to read the optically encoded QR code are presented. To the best of our knowledge, this is the first report on integrating photon-counting security with optically phase encoded QR codes.