Probabilistic Quantum Teleportation via 3-Qubit Non-Maximally Entangled GHZ State by Repeated Generalized Measurements

We propose a scheme of repeated generalized Bell state measurement (GBSM) for probabilistic quantum teleportation of single qubit state of a particle (say, 0) using 3-qubit non-maximally entangled (NME) GHZ state as a quantum channel. Alice keeps two qubits (say, 1 and 2) of the 3-qubit resource and the third qubit (say, 3) goes to Bob. Initially, Alice performs GBSM on qubits 0 and 1 which may lead to either success or failure. On obtaining success, Alice performs projective measurement on qubit 2 in the eigen basis of $\sigma_{x}$. Both these measurement outcomes are communicated to Bob classically, which helps him to perform a suitable unitary transformation on qubit 3 to recover the information state. On the other hand, if failure is obtained, the next attempt of GBSM is performed on qubits 0 and 2. This process of repeating GBSM on alternate pair of qubits may continue until perfect teleportation with unit fidelity is achieved. We have obtained analytical expressions for success probability up to three repetitions of GBSM. The success probability is shown to be a polynomial function of bipartite concurrence of the NME resource. The variation of success probability with the bipartite concurrence has been plotted which shows the convergence of success probability to unity with GBSM repetitions.Comment: 11 pages, 5figure

A Study of Temperature-dependent Fluid Properties on MHD Free Stream Flow and Heat Transfer over a Non-Linearly Stretching Sheet

AbstractAn analysis has been done for non-linearly stretching sheet with temperature-dependent fluid properties with free stream mag- netohydrodynamic (MHD) flow. The transverse magnetic field and the stretching velocity are assumed to vary as a power of the distance. The thermal conductivity shows linear variation whereas the fluid viscosity varies inversely with temperature. We have incorporated similarity transformations in our study to mould partial differential equations into non-linear equations. These equations are solved using Runge-Kutta Fehlberg method with the shooting techniques. In the present study, we discuss effects of various fluid parameters on the profiles of velocity and temperature in the presence of free stream. The effect with variations of these parameters has been investigated. We found that the free stream velocity reduces the boundary layer thickness

Audio and image encryption scheme based on QR decomposition and random modulus decomposition in Fresnel domain

In this paper, an asymmetric audio and image encryption mechanism using QR decomposition and random modulus decomposition (RD) in the Fresnel domain is proposed. The audio file is recorded as a vector and converted to a two-dimensional array to act as an image or a sound map. This sound map is encrypted using the image encryption algorithm proposed in this paper. The proposed cryptosystem is validated for both audios and grayscale images. Fresnel parameters and the two private keys obtained from QR decomposition and random modulus decomposition (RD) form the key space. Computer-based reproductions have been carried out to prove the validity and authenticity of the scheme. Simulation results authenticate that the scheme is robust and efficient against various attacks and is sensitive to input parameters

Stability analysis of MHD outer velocity flow on a stretching cylinder

A study has been done on axisymmetric magnetohydrodynamic (MHD) flow of a viscous incompressible outer velocity fluid along a stretching cylinder. The momentum and heat partial differential equations are mold using similarity transformations into a set of nonlinear ordinary differential equations. These equations have been solved with the help of Runge-Kutta Fehlberg scheme numerically with shooting technique. It is found that the solution is not unique for stretching cylindrical surface. The dual solution exists for a certain range of fluid parameters on stretching surface. The stability analysis shown that the upper branch is a stable solution and the lower branch is a unstable solution. The critical point λc=-0.03211 of outer velocity parameter and the range of the unstable solution -0.03211=λc⩽λ⩽λr=0.1411 have been obtained for certain magnetic parameter. Also, the effects of MHD and outer velocity parameter with various other fluid parameters on heat transfer and flow characteristics have been analyzed and shown by figures and tables. The outcomes show that the outer velocity parameter has a substantial effect on MHD fluid flow in stretching cylindrical surface. Keywords: Stability analysis, MHD, Stretching cylinder, Heat transfer, Outer velocity, Dual solutio

Asymmetric double-image encryption using twin decomposition in fractional Hartley domain

Twin decomposition, consisting of equal and random modulus decompositions, not only makes a cryptosystem asymmetric but also resists special attack. A new double-image asymmetric crypto-system using twin decomposition in fractional Hartley domain is proposed. An input grayscale image, bonded with another grayscale image as its phase mask, is transformed via fractional Hartley transform. Equal modulus decomposition is applied on the resulting image, giving us two intermediate images. One of them is subjected to another fractional Hartley transform followed by random modulus decomposition, whereas the other serves as the first private key. The application of random modulus decomposition also results in two images: encrypted image and the second private key. During the process of decryption, firstly the encrypted image is combined with second private key and thereafter it is subjected to inverse fractional Hartley transform. The resulting image is then combined with the first private key, and followed by another inverse fractional Hartley transform, thus recovering the two original images. The proposed cryptosystem is validated for pairs of grayscale images

Asymmetric double image encryption, compression and watermarking scheme based on orthogonal-triangular decomposition with column pivoting

A novel asymmetric scheme for double image encryption, compression and watermarking based on QR decomposition in the Fresnel domain has been presented. The QR decomposition provides a permutation matrix as a ciphertext, and the product of orthogonal and triangular matrix as a key. The ciphertext obtained through this process is a sparse matrix that is compressed by the CSR method to give compressed encrypted data, which when combined with a host image, gives a watermarked image. Thus, a cryptosystem that involves compression and watermarking is proposed. The proposed scheme is validated for grayscale images. To check the efficacy of the proposed scheme, histograms, statistical parameters, and key sensitivity are analyzed. The scheme is also tested against various attacks. Numerical simulations are performed to validate the security of the scheme