Block based Data Encryption and Decryption using Number System Logic

Cryptography is the automated (or algorithmic) method in which security goals are accomplished. Typically, when we say “crypto algorithm” we are discussing an algorithm meant to be executed on a computer. These algorithms operate on messages in the form of groups of bits. Here we introduced a Block based symmetric key encryption algorithm, which is based on simple mathematical operation. In this algorithm encryption is done on binary file so it can be applicable for any type of data such a text as well as multimedia data [3]-[9]. For encryption a key is to be generated. Key length and bit stream is chosen at random. At first, the plain text has been converted into its binary form and then the binary file is divided into some blocks. The block length is our key and it’s choosing randomly. Our algorithm is based on the following method:-- If the sum of each digit of a number is subtracted from that number, then the result is obviously divisible by a particular number [5]-[8]. This is the foundation of our algorithm.