Abstract
A Genetic Algorithm is defined as a smart algorithm which can be used to solve the complex matters and improve them, which are used in many fields. Also, Genetic Algorithm is considered as one of the efficient search methods which depends on the natural test and genetics. In this research, the Genetic Algorithm features were used to determined and find the encrypted key which was used to encrypt a plain-text by firstly using many selected random generated keys, then apply the Genetic Algorithm with its different features such as: selection, crossover and mutation, leading to the most efficient key to attack the cipher-text and return it to its plain-text with very small or non error ratio. Thus the user will be able to use this key to attack other coming texts for the same destination. The GA which is used in this paper were applied on a different English texts. Results showed the importance of Genetic Algorithm through its potentiality in wide space intelligent search of keys to find the right key, from the other hand, these results showed the accuracy of Genetic Algorithm during its approach.