Penerapan CIELab Dan Chaos Sebagai Cipher Pada Aplikasi Kriptografi Citra Digital

The development of Internet supports people to transmit information, such as text, images and other media quickly. However, digital images transmitted over the Internet are very vulnerable to attacks, for examples modification and duplication by unauthorized people. Therefore, cryptography as one of method for data security has been developed. This research proposed a combination of color structure CIELab and key randomization by logistic map from chaos as new cipher in digital image cryptographic applications. Cipher is applied to the encryption and decryption process. Implementation of new cipher in cryptographic digital images application was built with Matlab R2010a. Based on the research that has been done, it was found that combination CIELab and chaos can be applied as a new cipher on the encryption and decryption of digital images for cryptographic applications with processing time less than 1 second. Under possible maximum key range on RGB image by 5,2x 1033, the cipher was sufficiently secure against brute-force attack. Decrypted image has good quality with PSNR greater than 50 dB for digital image formatted in “tiff” and “png”

An Efficient Data Security System Using Reserve Room Approach on Digital Images for Secret Sharing

This paper presents enhancement of d ata protection system for secret communication through common network based on reversible data concealment in encrypted images with reserve room approach. In this paper was implemented for true color RGB image and reserve room approach under multi scale decomposition. The Blue plane will be chosen for hiding the secret text data. Then image is then separated into number of blocks locally and lifting wavelet will be used to detect approximation and detailed coefficients. Then approximation part is encrypted using chaos encryption method. The proposed encryption technique uses the key to encrypt an image and not only enhances the safety of secret carrier informa tion by making the information inaccessible to any intruder having a random method. After image encryption, the data hide r will conceal the secret data into the detailed coefficients which are reserved before encryption. Although encryption achieves certain security effects, they make the secret messages unreadable and unnatural or meaningless. This system is still enhanced with encrypt messages using a symmetric key method. This is the reason a new security approach called reversible data hiding arises. It is the art of hiding the existence of data in another transmission medium to achieve secret communication. The data hidi ng technique uses the adaptive LSB replacement algorithm for concealing the secret message bits into the encrypted image. In the data extraction module, the secret data will be extracted by using relevant key for choosing the encrypted pixe ls to extract th e data. By using the decryption keys, the image and extracted text data will be extracted from encryption to get the original informatio n. Finally the performance of this proposal in encryption and data hiding will be analyzed based on image and data recovery

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

A Novel Latin Square Image Cipher

In this paper, we introduce a symmetric-key Latin square image cipher (LSIC) for grayscale and color images. Our contributions to the image encryption community include 1) we develop new Latin square image encryption primitives including Latin Square Whitening, Latin Square S-box and Latin Square P-box ; 2) we provide a new way of integrating probabilistic encryption in image encryption by embedding random noise in the least significant image bit-plane; and 3) we construct LSIC with these Latin square image encryption primitives all on one keyed Latin square in a new loom-like substitution-permutation network. Consequently, the proposed LSIC achieve many desired properties of a secure cipher including a large key space, high key sensitivities, uniformly distributed ciphertext, excellent confusion and diffusion properties, semantically secure, and robustness against channel noise. Theoretical analysis show that the LSIC has good resistance to many attack models including brute-force attacks, ciphertext-only attacks, known-plaintext attacks and chosen-plaintext attacks. Experimental analysis under extensive simulation results using the complete USC-SIPI Miscellaneous image dataset demonstrate that LSIC outperforms or reach state of the art suggested by many peer algorithms. All these analysis and results demonstrate that the LSIC is very suitable for digital image encryption. Finally, we open source the LSIC MATLAB code under webpage https://sites.google.com/site/tuftsyuewu/source-code.Comment: 26 pages, 17 figures, and 7 table