International Science and Technology Journal

Public Key Cryptography has been widely accepted as the method in which data is encrypted using some algorithms such as the widely known and commonly used RSA algorithm. However, management of the public-key and its storage is an on-going issue. To avoid these problems the symmetric key approach can be used, where there is only one key which it can be used for both encryption and decryption process and it must be kept secret. In this paper, a particular symmetric key cryptosystem is presented. The main focus of this paper is to encrypt and decrypt text and image data for the purpose of protecting intellectual properties. The text encryption performed by converting the text data into image and then the resulted image is coded using block truncation coding (BTC) technique and finally XOR operation between the coded image data and a randomly generated binary matrix is performed. The main advantages of the proposed cryptosystem represented in the provided high level of security since breaking this cryptosystem depends on breaking its encryption and decryption key. The key is randomly generated in a form of binary matrix which makes it really hard even impossible to be broken.