سعد عبدالسادة غني العبودي

Nowadays, text encryption is recommendable when it is transmitted or stored on insecure channels as Internet. In this paper we introduced novel method to encrypt text based on SVD. Up to our knowledge this is the first paper encrypted text by using SVD. The message is the composition of some character. Every character of the message can be represented as an ASCII value, and then we can build numeric matrix for each text. We suggested using other text as key and using with plaintext to scramble the plaintext prior to use the SVD process which makes cryptanalyst’s job difficult. There are many difficulties in using the SVD to encrypt text. The decrypted text was the same as the plaintext without loss any character. Encryption and decryption time were reasonable. One of the important features of this work is the ability to produce encrypted text with language differ from the plaintext language which make add more complixity of decrypt the encrypted text from third party.

Laplace transformations have wide applications in engineering and sciences. All previous studies of modified Laplace transformations depend on differential equation with initial conditions. The purpose of our paper is to solve the linear differential equations (not initial value problem) and then find the general solution (not particular) via the Laplace transformations without needed any initial condition. The study involves both types of differential equations, ordinary and partial.