On the Design of Perceptual MPEG-Video Encryption Algorithms

In this paper, some existing perceptual encryption algorithms of MPEG videos are reviewed and some problems, especially security defects of two recently proposed MPEG-video perceptual encryption schemes, are pointed out. Then, a simpler and more effective design is suggested, which selectively encrypts fixed-length codewords (FLC) in MPEG-video bitstreams under the control of three perceptibility factors. The proposed design is actually an encryption configuration that can work with any stream cipher or block cipher. Compared with the previously-proposed schemes, the new design provides more useful features, such as strict size-preservation, on-the-fly encryption and multiple perceptibility, which make it possible to support more applications with different requirements. In addition, four different measures are suggested to provide better security against known/chosen-plaintext attacks.Comment: 10 pages, 5 figures, IEEEtran.cl

Synchronization of spatiotemporal semiconductor lasers and its application in color image encryption

Optical chaos is a topic of current research characterized by high-dimensional nonlinearity which is attributed to the delay-induced dynamics, high bandwidth and easy modular implementation of optical feedback. In light of these facts, which adds enough confusion and diffusion properties for secure communications, we explore the synchronization phenomena in spatiotemporal semiconductor laser systems. The novel system is used in a two-phase colored image encryption process. The high-dimensional chaotic attractor generated by the system produces a completely randomized chaotic time series, which is ideal in the secure encoding of messages. The scheme thus illustrated is a two-phase encryption method, which provides sufficiently high confusion and diffusion properties of chaotic cryptosystem employed with unique data sets of processed chaotic sequences. In this novel method of cryptography, the chaotic phase masks are represented as images using the chaotic sequences as the elements of the image. The scheme drastically permutes the positions of the picture elements. The next additional layer of security further alters the statistical information of the original image to a great extent along the three-color planes. The intermediate results during encryption demonstrate the infeasibility for an unauthorized user to decipher the cipher image. Exhaustive statistical tests conducted validate that the scheme is robust against noise and resistant to common attacks due to the double shield of encryption and the infinite dimensionality of the relevant system of partial differential equations.Comment: 20 pages, 11 figures; Article in press, Optics Communications (2011

Digital Image Encryption Technique using Block Based Scrambling and Substitution

A novel non-chaos based digital image encryption technique using a combination of diffusion and substitution process has been presented. A secret key of 128 bit sizes is used in the algorithm. In the diffusion (permutation) method, image is divided into different dynamic blocks which are key dependent. Further, each block is made to pass through eight rounds of permutation process. In this process, a zigzag mechanism is used to scramble the block pixels within the block. Then the resultant image i.e. the partially encrypted image is divided into various key based dynamic sub-images. Pixels of the sub-images are replaced with another pixel values within the block when each of the sub-images are passed through the substitution process. The substitution process comprises of four rounds. The proposed scheme is then compared with the standard AES algorithm. Investigation outcome shows that the proposed design methodology is efficient, fast and secur

Recent Trends in Image Encryption: A Review

Security of multimedia data is gaining acceptance owing to the growth and acceptability of images in various applications and in telecommunication. Encryption is one of the ways to ensure high security of images as they are used in many fields such as in secure medical imaging services, military intelligence, internet and intranet communication, e-banking etc. These images are stored or transmitted through a network; hence the security of such image data is important. In this work, recently developed encryption techniques are studied and analyzed to promote further development of more encryption methods to ensure additional security and versatility. All the techniques reviewed came into existence within the last five years (2011-2015) and are found to be useful for the present day encryption applications. Each technique is unique in its own way, which might be suitable for different applications. As time goes on, new encryption techniques are evolving. Hence, fast and secure conventional encryption techniques will always be needed in applications requiring high rate of security