Plaintext-related Image Research Articles

Cryptanalysis and Improvement in a Plaintext-Related Image Encryption Scheme Based on Hyper Chaos

Recently, a plaintext-related image encryption scheme based on a hyper-chaotic system has been proposed by Li et al . In their encryption scheme, the permutation process is related to the sum of plaintext pixel values, and the diffusion process is related to the values of nine special positions in the permuted image. This can resist the existing chosen plaintext attack due to the ever-changing permutation matrix and diffusion matrix when the plaintext is changed. Here, we show that Li’s encryption scheme contains two vulnerabilities. First, the gray values of the nine specific pixels do not change during diffusion. Second, the permutation process is reversible. Therefore, the diffusion process can be attacked and the permuted image can be obtained by constructing a special image, where the nine special position values in the special image’s permuted image are the same as those in the cipher image. Then, if the obtained permuted image is chosen as plaintext, we can get its permuted image by attacking the diffusion process. Since the permutation process is reversible, the permuted image is the original plaintext image. In addition, some improvements for Li’s encryption scheme are provided to enhance the security.

A Novel Plaintext-Related Image Encryption Algorithm Based on Stochastic Signal Insertion and Block Swapping

Image encryption is an important method for protecting private data during communication. This paper proposes a novel hyperchaotic image encryption algorithm based on stochastic signal insertion and block permutation. First, the 5D hyperchaotic system is applied to generate pseudorandom number sequences. The SHA-256 hash function and secret keys are used to produce the initial values of the cryptosystem. The hash values can effectively enhance the sensitivity to plain image. To enlarge the key space and change orbit of cryptosystem, some stochastic signals are inserted during iteration. The plain image is equally divided into two parts. An X-coordinate, a Y-coordinate and a control table are established with produced pseudonumber sequences. The pixel is swapped with another pixel in the current block or another block depending on the control table. Cyclic shift is performed during the diffusion process. Performance and security analyses are executed to verify the effect of the proposed scheme. It is clear that the proposed scheme has a large key space and is highly sensitive to plain image and secret keys. Moreover, the cryptosystem has low computation complexity and can resist correlation analysis, entropy analysis, statistical attack, differential attack, noise and data loss attacks.

A novel plaintext-related image encryption scheme using hyper-chaotic system

A novel and secure plaintext-related image encryption scheme is given in this paper using hyper-chaotic Lorenz system and hash function. In our scheme, we used the classical encryption architecture: permutation and diffusion. The initial conditions of hyper-chaotic Lorenz system which is employed in permutation and key stream generation algorithms are generated by information of the original image and initial key. Therefore, the encryption process has a strong relationship with plain image in the proposed scheme. So, our work performs excellently on resisting the known-plaintext attack. In addition, results of many widely used security analyses and comparisons with other works show that our work has outstanding security performance for the digital image communication.

A plaintext-related image encryption algorithm based on chaos

A symmetric key image cryptosystem based on the piecewise linear map is presented in this paper. In this cryptosystem, the encryption process and the decryption process are exactly same. They both ...

The image encryption algorithm with plaintext-related shuffling

ABSTRACTThis paper proposed a plaintext-related image encryption system, which employed the hyper-chaotic system to generate the secret code streams used for encryption. The encryption algorithm includes two plaintext-unrelated diffusion operations and one plaintext-related shuffling. Due to the use of plaintext-related shuffling, the proposed encryption system can resist the chosen/known plaintext attacks. Simulation results show that the proposed system has many good characters, such as fast encryption speed, large key space, high key sensitivity, effectively resisting differential attack, noise-like cipher-text image, etc., and thus can be used in actual communications.

A Chaotic System Based Image Encryption Algorithm using Plaintext-related Confusion

A new plaintext-related image encryption system based on the hyper-chaotic Lorenz system is proposed in this paper. In the proposed image encryption system, the hyper-chaotic Lorenz system is employed to generate six pseudo-random matrixes, where, two of them use the “add-modulus” operations to carry out the plaintext-unrelated image diffusion, and the other four matrixes are used to confuse the plaintext-related image. In the image confusion, each pixel will swap its location with another pixel, and the target location is determined by some elements in the plain image and the four matrixes. The proposed image encryption system can resist the chosen/known plaintext attacks due to the application of the plaintext-related image confusion in it. The simulation results show that the proposed encryption system also have the characters of fast encryption/decryption speed, large key space, strong key sensitivity, strong plaintext sensitivity, good statistical properties of cipher images, and large information entropy, etc. Thus, the proposed system can be used in practical communications.

Plaintext Related Image Encryption Scheme Using Chaotic Map

A plaintext related image blocking encryption algorithm is proposed in this paper, which includes two kinds of operations on inner-block confusion and inter-block diffusion. Firstly, a float-point lookup table need to be generated by iterating chaotic system; Secondly, choose one of the entries in the look-up table as initial value of chaotic system, and iterate it to produce one secret code sequence for inner-block confusion; Thirdly, by using one pixel value of the former block to locate another entry in the look-up table, iterate it to yield another secret code sequence for inter-block diffusion; Finally, through two rounds of the block-by-block processes, the plain-image will be transformed into the cipher-image. The simulation results show that the proposed method has many good characters. DOI : http://dx.doi.org/10.11591/telkomnika.v12i1.3482