A novel medical image protection scheme using a 3-dimensional chaotic system

A one-round medical image encryption algorithm based on a combined chaotic key generator

Medical images of patients must be securely transmitted and kept private in telemedicine. To secure such medical images, this paper proposes a single round chaotic image encryption scheme based on a permutation-diffusion structure. A combined chaotic key generator (CCKG) is proposed to enhance key sensitivity and generation in order to improve the security of medical images to be encrypted. CCKG is used to produce the initial seeds for the fractional order chaotic system (FOCS) and Lorenz system (LS) for the permutation and diffusion processes, respectively. CCKG together with proposed permutation and diffusion methods enhances cipher image security in single round. Using zigzag transform (ZT) scanning, the plain image is first permuted block by block. The type of scanning used on each block is heavily influenced by the ZT selection from FOCS and LS. Following block-wise permutation, the permutation order (PO) generated from LS performs overall permutation. Based on the pixel positions, the overall permuted image is divided into odd and even parts. Then these parts of the images are diffused separately by the random pixel matrices generated by LS and FOCS. The cipher image is formed by combining the odd and even parts after diffusion. Secret key analysis, statistical analysis, differential attack analysis, and simulations confirm that with a single round of image encryption, the proposed system is competent, robust and effective.

Medical image encryption based on biometric keys and lower-upper decomposition with partial pivoting

The security of medical image transmission in telemedicine is very important to patients' privacy and health. A new asymmetric medical image encryption scheme is proposed. The medical image is encrypted by two spiral phase masks (SPM) and the lower-upper decomposition with partial pivoting, where the SPM is generated from the iris, chaotic random phase mask, and amplitude truncated spiral phase transformation. The proposed scheme has the following advantages: First, the iris is used for medical image encryption, which improves the security of the encryption scheme. Second, the combination of asymmetric optical encryption and three-dimensional Lorenz chaos improves the key space and solves the linear problem based on double-random phase encoding. Third, compared with other encryption schemes, the proposed scheme has advantages in occlusion attacks, key space, correlation, and information entropy. Numerical simulation and optical results verify the feasibility and robustness of the encryption scheme.

Medical image encryption using fractional discrete cosine transform with chaotic function

In this advanced era, where we have high-speed connectivity, it is very imperative to insulate medical data from forgery and fraud. With the regular increment in the number of internet users, it is challenging to transmit the beefy medical data. This (medical data) is always reused for different diagnosis purposes, so the information of the medical images need to be protected. This paper introduces a new scheme to ensure the safety of the medical data, which includes the use of a chaotic map on the fractional discrete cosine transform (FrDCT) coefficients of the medical data/images. The imperative FrDCT provides a high degree of freedom for the encryption of the medical images. The algorithm consists of two significant steps, i.e., application of FrDCT on an image and after that chaotic map on FrDCT coefficients. The proposed algorithm discusses the benefits of FrDCT over fractional Fourier transform (FRFT) concerning fractional order α. The key sensitivity and space of the proposed algorithm for different medical images inspire us to make a platform for other researchers to work in this area. Experiments are conducted to study different parameters and challenges. The proposed method has been compared with state-of-the-art techniques. The results suggest that our technique outperforms many other state-of-the-art techniques. Graphical Abstract Overview of the proposed algorithm.

Networked medical data sharing on secure medium - A web publishing mode for DICOM viewer with three layer authentication

Growing demand for e-healthcare across the globe has raised concerns towards the secure and authentication enhanced medical image sharing. One of the services offered by health informatics in hospitals include an user interface through the Local Area Network (LAN) for enabling storage and access of medical records. In this paper, a security enhanced DICOM image sharing over a LAN addressing confidentiality, integrity and authentication has been proposed. Initially, the AES encrypted patient history was combined along with the thumb impression and Quick Response (QR) code of patient ID as watermark. This watermark was encrypted employing Integer Wavelet Transform (IWT), chaotic map and attractors with confusion-diffusion operations. Further, the encrypted watermark was embedded in the selected Region Of Non-Interest (RONI) pixels of DICOM image. Username & unique password credentials, Face identification and FPGA generated One Time Password (OTP) form the three layer authentication scheme for secure DICOM image access through the LAN. Web publishing medium of storing secured DICOM images in cloud has also been addressed in this work. To validate the proposed hybrid crypto-watermarking system, parameters such as key sensitivity, key space, correlation, entropy, histogram, cropping attack, Mean Square Error (MSE), Peak Signal to Noise Ratio (PSNR) and Structural Similarity Index Metric (SSIM) were performed and the results obtained have proved the strength of the proposed algorithm against brute force, statistical and cropping attacks.

Medical Images are Safe - an Enhanced Chaotic Scrambling Approach

The patient data confidentiality is one of the vital security aspects in e-Health and m-Health services. In particular, providing confidentiality to the patient's medical image is essential and the protection approaches have to be explored in-depth due to the rapid progress in the technologies of teleradiology and PACS. In this study, the pseudo random number generators (PRNGs), namely, the linear congruential generator (LCG) and XOR shift generator (XSG) are improved and combined with improved logistic 2D coupled chaotic map to provide enhanced chaos based encryption. The proposed scheme encrypts the Digital Imaging and Communication in Medicine (DICOM) images to protect the patient confidentiality during the storage and transfer in radiological information system (RIS). The cipher image was measured with various security analyses and tested with different test suites to prove its randomness.

A Fast Color Image Encryption Algorithm Using 4-Pixel Feistel Structure

Algorithms using 4-pixel Feistel structure and chaotic systems have been shown to resolve security problems caused by large data capacity and high correlation among pixels for color image encryption. In this paper, a fast color image encryption algorithm based on the modified 4-pixel Feistel structure and multiple chaotic maps is proposed to improve the efficiency of this type of algorithm. Two methods are used. First, a simple round function based on a piecewise linear function and tent map are used to reduce computational cost during each iteration. Second, the 4-pixel Feistel structure reduces round number by changing twist direction securely to help the algorithm proceed efficiently. While a large number of simulation experiments prove its security performance, additional special analysis and a corresponding speed simulation show that these two methods increase the speed of the proposed algorithm (0.15s for a 256*256 color image) to twice that of an algorithm with a similar structure (0.37s for the same size image). Additionally, the method is also faster than other recently proposed algorithms.

Secured Medical Images - a Chaotic Pixel Scrambling Approach

In this paper, a cryptosystem is proposed to encrypt 16-bit monochrome DICOM image using enhanced chaotic economic map. A new enhanced chaotic economic map (ECEM) is designed from the chaotic economic map which has better bifurcation nature and positive Lyapunov exponent values. In order to improve the sternness of the encryption algorithm, the enhanced chaotic map is employed to generate the pixel permutation, masking, and swapping sequences. The substitution operation is introduced in-between the standard permutation and diffusion operations. The robustness of the proposed image encryption algorithm is measured by various analyses such as histogram, key sensitivity, key space, number of pixel change rate (NPCR), unified average change intensity (UACI), information entropy and correlation coefficient. The results of the security analyses are compared with existing algorithms to validate that the proposed algorithm is better in terms of larger key space to resist brute force attacks and other common attacks on encryption.