A symmetric key cryptography using genetic algorithm and error back propagation neural network In conventional security mechanism, cryptography is a process of information and data hiding from unauthorized access. It offers the unique possibility of certifiably secure data transmission among users at different remote locations. Cryptography is used to achieve availability, privacy and integrity over different networks. Usually, there are two categories of cryptography i.e. symmetric and asymmetric. In this paper, we have proposed a new symmetric key algorithm based on genetic algorithm (GA) and error back propagation neural network (EBP-NN). Genetic algorithm has been used for encryption and neural network has been used for decryption process. Consequently, this paper proposes an easy cryptographic secure algorithm for communication over the public computer networks.