Sivaraman Rethinam

Bio: Sivaraman Rethinam is an academic researcher from Shanmugha Arts, Science, Technology & Research Academy. The author has contributed to research in topics: Encryption & Confusion and diffusion. The author has an hindex of 4, co-authored 19 publications receiving 74 citations.

Networked hardware assisted key image and chaotic attractors for secure RGB image communication

Abstract: In multimedia communication, significance of the images for data representation is noteworthy. In this context, secure transmission of images over open channel has become a challenging task. Creation of different strategies in improving the secure image transmission always has a demand. The proposed work suggests an RGB image encryption with the confluence of attractors and hardware triggered key image in which confusion and diffusion were accomplished by Lorenz, Lu and Cellular Automata attractors. The uniqueness of proposed encryption scheme is a key image generation module through cascaded Ring Oscillator circuit which creates M × N key image for diffusion of pixels. Facilitating the authenticated networked access to key image generation hardware enables the secure server-client architecture for a variety of secure image transfer applications. The proposed approach is a hardware – software codesign which possesses a good keyspace, improved key sensitivity and satisfies the various statistical parameters thus offering substantial resistance to differential, occlusion and chosen plaintext attacks on RGB images.

Chua's diode and strange attractor: a three-layer hardware–software co-design for medical image confidentiality

Abstract: Medical image security relies upon the arrival of improved techniques for enhancing the confusion as well as diffusion processes in the pixel level manipulations. Non-linear circuits constructed with hardware components can be employed for hardware–software co-design in medical image encryption. The proposed approach has adopted Chua diode circuit for the generation of 256 × 256 random synthetic image with the entropy of 7.9972. This synthetic image has been utilised to scramble the DICOM image for the second level of diffusion as the cellular automata provides the first level of scrambling and diffusion. The average correlation coefficients of encrypted pixels are 0.00204, −0.00298 and −0.00054 in three directions. The encrypted pixels pass the NIST SP 800-22 test suite and offer resistance to statistical, differential and chosen plain text attacks.

IoT Framework for Secure Medical Image Transmission

Abstract: Medical image encryption plays a pivotal role in telemedicine and healthcare applications Authentication of medical images require a must attention owing to the amount of medical data being communicated and number of digital records being created and maintained In this work, a server - client model of authenticated medical image communication is proposed Initially, the AES encrypted medical image is further secured by embedding a One Time Password (OTP) generated through Tent map This OTP embedded image is shared to the intended user via intranet Upon receiving the OTP through GSM, the authorized user verifies the similarity of received OTP in mobile and extracted one from the encrypted medical image After integrity checking, the decryption is performed to retrieve the original medical record The proposed work of medical image encryption has been developed using python 27 and validated by performing entropy, correlation, differential, error metric and NIST test analyses

Jitters through dual clocks: An effective Entropy Source for True Random Number Generation

Abstract: True random number generators (TRNG) have an appreciable demand in key generation of crypto processors FPGA based TRNGs offer various advantages for generation, packing and storage Metastability, jitter, race around and memory collision are some of the entropy sources for extraction of true randomness In this work, jitter extraction is the prime focus for randomness harvesting Two different frequencies have been generated by Onchip PLL of FPGA which were used in an asynchronous manner for random bit generation Two Flip-flops have been used in this design after which post processing unit enhances the randomness Both Von - Neumann Corrector as well as 1D logistic map have been experimented as post processing functions Randomness of the numbers was tested and ensured by performing entropy analysis as well as NIST tests This proposed TRNG has been designed using VHDL and implemented on Altera Cyclone II EP2C35F672C6N FPGA consuming 1298 logic elements with a throughput of 2684 Mbps

Cellular automata + LFSR + synthetic image: A trio approach to image encryption

Abstract: Image encryption plays a crucial role in modern day secure multimedia communication. Confusion and diffusion are the two important mechanisms to encrypt the images employed in most of the image encryption schemes. In this paper, a grayscale image encryption method has been proposed with the confluence of Linear Feedback Shift Register (LFSR), Cellular Automata (CA) and hardware generated synthetic image. CA manages scrambling as well as diffusion. LFSR generates diffused bits which are sampled with hardware created clock source on Cyclone II FPGA in order to generate synthetic image. Synthetic image obtained through this random sampling process on FPGA enhances the randomization of encrypted images which has been evaluated with parameters such as entropy, correlation, histogram, differential, encryption quality and error metric analyses. The encryption and decryption processes were implemented using LabVIEW 2013 platform.

When an attacker meets a cipher-image in 2018: A year in review

Abstract: This paper aims to review the encountered technical contradictions when an attacker meets the cipher-images encrypted by the image encryption schemes (algorithms) proposed in 2018 from the viewpoint of an image cryptanalyst. The most representative works among them are selected and classified according to their essential structures. Almost all image cryptanalysis works published in 2018 are surveyed due to their small number. The challenging problems on design and analysis of image encryption schemes are summarized to receive the attentions of both designers and attackers (cryptanalysts) of image encryption schemes, which may promote solving scenario-oriented image security problems with new technologies.

A review of entropy measures for uncertainty quantification of stochastic processes

Abstract: Entropy is originally introduced to explain the inclination of intensity of heat, pressure, and density to gradually disappear over time. Based on the concept of entropy, the Second Law of Thermody...

Advanced framework for highly secure and cloud-based storage of colour images

Abstract: The evergrowing virtualised information technology infrastructure is powered by cloud-centric technology around the world Cloud-based multimedia storage has become an essential aspect for users and business behemoths However, as per a survey of Norton, around 3800 breaches have been publicly disclosed with 41 billion numbers of records exposed in 2019, which is a 54% rise when compared to 2018 So the data security is a widely quoted barrier for cloud storage Ciphering the confidential images before transmission and subsequent storage in cloud database needs critical attention for techno-specific applications In image encryption, chaos-based keys can do better confusion, but the diffusion process using XOR is vulnerable to chosen plain text attack The proposed colour image encryption scheme innately uses Deoxyribo Nucleic Acid coding that blends well with chaotic cryptosystem for an efficient statistical shift The ciphered images are stored in authenticated and authorised cloud storage facilities The experimentation is carried out with the help of Amazon Web Services storage instances The proposed image encryption scheme offers a strong resistance towards the brute force, occlusion, statistical and differential attacks and yields near-zero correlation and good entropy

Ring oscillator as confusion – diffusion agent: a complete TRNG drove image security

Abstract: The utility of true random number generators (TRNGs) is not only restricted to session key generation, nonce generation, OTP generation etc. in cryptography. In the proposed work, two ring oscillator (RO) based TRNG structures adopting identical and non-identical ring of inverters have alone been employed for confusion (scrambling) and diffusion (intensity variation) processes for encrypting the greyscale and RGB images. Cyclone IVE EP4CE115F29C7 FPGA was utilised to generate a couple of random synthetic images using the two RO architectures which took a maximum of 520 combinational units and 543 logic registers. The suggested scheme of image encryption was tested on 100 test greyscale images of size 256 × 256. This non-chaos influenced image ciphering has resulted in an approximate average entropy of 7.99 and near-zero correlation figures for the greyscale & RGB cipher images. The attack resistance capability was checked by performing various occlusion and noise attacks on encrypted images.