Inversion of a perturbed matrix

Inversion of a perturbed matrix

An efficient formula is developed for computing the inverse of a given matrix perturbed by any diverting matrix. The matrix entries may be scattering within this diverting matrix. © 2005 Elsevier Ltd. All rights reserved.

A stable iteration to the matrix inversion

The matrix inversion plays a signifcant role in engineering and sciences. Any nonsingular square matrix has a unique inverse which can readily be evaluated via numerical techniques such as direct methods, decomposition scheme, iterative methods, etc. In this research article, first of all an algorithm which has fourth order rate of convergency with conditional stability will be proposed. ...

Detection of perturbed quantization (PQ) steganography based on empirical matrix

Perturbed Quantization (PQ) steganography scheme is almost undetectable with the current steganalysis methods. We present a new steganalysis method for detection of this data hiding algorithm. We show that the PQ method distorts the dependencies of DCT coefficient values; especially changes much lower than significant bit planes. For steganalysis of PQ, we propose features extraction from the e...

Perturbed Hidden Matrix Cryptosystems

We apply internal perturbation [3] to the matrix-type cryptosystems [Cn] and HM constructed in [9]. Using small instances of these variants, we investigate the existence of linearization equations and degree 2 equations that could be used in a XL attack. Our results indicate that these new variants may be suitable for use in practical implementations. We propose a specific instance for practica...

Matrix Inversion Made Difficult