A new substitution block cipher using genetic algorithm

In cryptography, a substitution block cipher is a method of encryption by which units of plain text are replaced with cipher text according to a regular system. The receiver deciphers the text by performing an inverse substitution. If the cipher operates on single blocks, it is termed as simple substitution block cipher. We proposed an algorithm which considers a random matrix key which on execution of a sequence of steps generates a sequence. Based on the equality of values, this sequence is being divided into basins. Each basin represents one block of data on which the genetic algorithm operations like crossover and mutation are performed. Each block of plain text is replaced by summation of ASCII value of plain text and the sequence is generated to form the cipher text. Thus, the cipher text obtained is very difficult to be broken without knowing the key, which provides high security.