An efficient 2048-bit block cipher

An Advanced Encryption Standard (AES) has been the most popular block cipher in the last two decades. It has been extensively analyzed and efficiently implemented. Since 2000, an AES has been preset to be upgradable from the current 128-bit key to 192-bit key and finally 256-bit key on the same 128-bit plain text-cipher text block. A new call for 256-bit standard symmetric cipher is expected by 2030. Currently, an input file runs in kilobytes. It is apparent that a more practical cipher is much needed in handling daily task of protecting an important document from a user stand point of view without having to go through technical knowledge of encryption. A symmetric cipher has been traditionally operated on a small block. In this paper, however, a new proposal on a large 2048-bit block cipher using 256-bit key is presented

A novel psychovisual model on an independent video frame for an almost lossless compression

A psychoacoustic model is well established in an audio coding. From the beginning of computer audio era since the previous century, an audio coding has already operated on a large one-dimensional fast Fourier transform (FFT) as a basic industrial coding. This paper investigates a quantitative experimental impact on almost lossless image compression based on the concept of psychovisual threshold. This paper proposes a practical image coding on large two-dimensional discrete cosine transform (DCT). A psychovisual model is presented following the psychoacoustic quite threshold as a just noticeable difference instead of a quantization table. An experimental result on large rectangular images shall be presented. This framework can easily produce higher quality images at a competitive compression rate in addition to an extended adaptive JPEG compression standard

A secure cryptographic algorithm against side channel attacks

Historically, a computing resource is scarce and expensive. In the last few decades, considerable efforts have been made to design efficient codes in terms of the storage space and running time. Due to the progress on computing resources and low cost of memory, an efficient algorithm has ironically become a vulnerable threat to cryptographic operations. An efficient unbalanced code opens another room for side channel attacks on the private key of public key infrastructure (PKI). This paper shall highlight and propose balanced secure algorithms for cryptographic operations to avoid feasible side channel attacks in the immediate future

AAβ-Cryptosystem: a chaos based public key cryptosystem

We describe the AAβ-cryptosystem, a new public key cryptosystem that is built by utilizing the classical one-way chaotic beta-transformati on mapping given by by fβ=βx (mod 1). The AAb-cryptosystem represents its private keys as a vector dA and uses the parallelogram law to prove that encryption and decryption does indeed occur. The mathematical hard problem for this system is likely to be harder than the classical Discrete Log Problem and to some extent probably equal or slightly better than the Elliptic Curve Discrete Log Problem (ECDLP). With the correct choice of a, β and generator point X(0), the generator point X(0)when iterated via the AAB function will have an order (i.e. period/cycle) of 2k-1 wheris the length of the private key. Because of this fact, the AAβ-Cryptosystem maybe more secure than the Elliptic Curve Cryptosystem (ECC)

An Image Dithering via Tchebichef Moment Transform

Many image display applications and printing devices allow only limited number of colours. They have limited computational power and storage to produce high quality outputs on high bit-depth colour image. A dithering technique is called for here in order to improve the perceptual visual quality of the limited bitdepth images. A dithered image is represented by a natural colour in the low bit depth image colour for displaying and printing. This technique obtains low cost colour image in displaying the colour and printing image pixels. This study proposes the dithering technique based on Tchebichef Moment Transform (TMT) to produce high quality image at low-bit colour. Earlier, a 2´2 Discrete Wavelet Transform (DWT) has been proposed for better image quality on dithering. The 2´2 TMT has been chosen here since it performs better than the 2´2 DWT. TMT provides a compact support on 2´2 blocks. The result shows that 2´2 TMT gives perceptually better quality on colour image dithering in significantly efficient fashio

A Generic Psychovisual Error Threshold for the Quantization Table Generation on JPEG Image Compression

The quantization process is a main part of image compression to control visual quality and the bit rate of the image output. The JPEG quantization tables are obtained from a series of psychovisual experiments to determine a visual threshold. The visual threshold is useful in handling the intensity level of the colour image that can be perceived visually by the human visual system. This paper will investigate a psychovisual error threshold at DCT frequency on the grayscale image. The DCT coefficients are incremented one by one for each frequency order. Whereby, the contribution of DCT coefficients to the error reconstruction will be a primitive pyschovisual error. At certain threshold being set on this psychovisual error, the new quantization table can be generated. The experimental results show that the new quantization table from psychovisual error threshold for DCT basis functions gives better quality image at lower average bit length of Huffman code than standard JPEG image compression

Introducing S-index into factoring RSA modulus via Lucas sequences

At any instance in the factoring algorithm, the accumulative result stands independently. In effect, there is no clear direction to manoeuvre whether to go left or right. General Lucas sequences are practically useful in cryptography. In the past quarter century, factoring large RSA modulo into its primes is one of the most important and most challenging problems in computational number theory. A factoring technique on RSA modulo is mainly hindered by the strong prime properties. The success of factoring few large RSA modulo within the last few decades has been due to computing prowess overcoming one strong prime of RSA modulo. In this paper, some useful properties of Lucas sequences shall be explored in factoring RSA modulo. This paper will also introduces the S-index formation in solving quadratic equation modulo N. The S-index pattern is very useful in designing an algorithm to factor RSA modulo. The S-index will add another comparative tool to better manoeuvre in a factoring process. On one hand, it shall remain a theoretical challenge to overcome the strong prime properties. On the other hand, it shall remain a computational challenge to achieve a running time within polynomial time to factor RSA modulo. This paper will propose an avenue to do both using general Lucas sequences

Psychovisual Threshold On Large Tchebichef Moment For Image Compression

JPEG standard transforms an 8×8 image pixel into a requency domain. The discontinuities of the intensity image between adjacent image blocks cause the visual artifacts due to inter-block correlations in image reconstruction. The blocking artifacts appear by the pixel intensity value discontinuities which occur along block boundaries. This research proposes the psychovisual threshold on large Tchebichef moment to minimize the blocking artifacts. The psychovisual threshold is practically the best measure for the optimal amount of frequency image signals in the image coding. The psychovisual threshold is a basic element prior to generating quantization tables in image compression. The psychovisual threshold on the large Tchebichef moments has given significant improvements in the quality of image output. The experimental results show that the smooth psychovisual threshold on the large discrete Tchebichef moment produces high quality image output and largely free of any visual artifacts