This paper presents several new properties of D sequences that have applications to encryption and error coding. It also considers the problem of joint encryption and error-correction coding and proposes a solution using D sequences. The encryption operation considered is equivalent to exponentiation, which forms the basis of several public-key schemes. An application of D sequences to generating events with specified probabilities is also presented.

Encryption and Error-Correction Coding Using D Sequences

We consider texture, luminance, corner and the edge information in the image to generate a mask that makes the addition of the watermark less perceptible to the human eye. The operation of embedding and extraction of the watermark is done in the frequency domain thereby providing robustness against common frequency-based attacks including image compression and filtering. We use decimal sequences for watermarking instead of pseudo random sequences, providing us with a greater flexibility in the choice of sequence. Weighted Peak Signal to Noise Ratio is used to evaluate the perceptual change between the original and the watermarked image

An Improved Method of Content Based Image Watermarking

This paper introduces the use of decimal sequences in a code division multiple access (CDMA) based watermarking system to hide information for authentication in black and white images. Matlab version 6.5 was used to implement the algorithms discussed in this paper. The advantage of using d-sequences over PN sequences is that one can choose from a variety of prime numbers which provides a more flexible system.

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Watermarking using decimal sequences

Many shares are generated from the secret images that are illogical containing certain message within them in visual cryptography. When all shares are piled jointly, they tend to expose the secret of the image. The multiple shares are used to transfer the secret image by using the encryption and decryption process by means of the elliptic curve cryptography (ECC) technique. In ECC method, the public key is randomly generated in the encryption process and decryption process, the private key (H) is generated by utilizing the optimization technique and for evaluating the performance of the optimization by using the peak signal to noise ratio (PSNR). From the test results, the PSNR has been exposed to be 65.73057, also the mean square error (MSE) value is 0.017367 and the correlation coefficient (CC) is 1 for the decrypted image without any distortion of the original image and the optimal PSNR value is attained using the cuckoo search (CS) algorithm when compared with the existing works.

RGB-Based Secure Share Creation in Visual Cryptography Using Optimal Elliptic Curve Cryptography Technique

This paper presents a survey of man-in-the-middle (MIM) attacks in communication networks and methods of protection against them. In real time communication, the attack can in many situations be discovered by the use of timing information. The most common attacks occur due to Address Resolution Protocol (ARP) cache poisoning, DNS spoofing, session hijacking, and SSL hijacking.

A Review of Man-in-the-Middle Attacks.

The properties of decimal sequences of rational numbers are investigated with the idea of using them as random sequences and error-correcting codes, and in other applications in communications. Several structural properties of decimal sequences are presented with special attention being given to binary decimal sequences and reciprocals of primes. For a certain class of decimal sequences of l/q, q prime, it is shown that the digits spaced half a period apart add up to r - 1 , where r is the base in which the sequence is expressed. Also for the same class all subsequences of length m , where r^{m} > q , are distinct. These underlying structural properties have made it possible to establish a lower bound on the Hamming distance between a given sequence and its cyclic shifts and also to obtain an upper bound on the autocorrelation function. A condition for the cross correlation of two decimal sequences being zero has also been obtained. The outcome of the calculations on decimal sequences of several primes is presented, and the results indicate that the autocorrelation function approximates that obtained for sequences of independent, equally likely random digits.

S. Kak

Papers

On decimal sequences (Corresp.)