A Cellular Automata (CA) is a computing model of complex System using simple rule. In this paper the problem space is divided into number of cell and each cell can be one or several final state. Cells are affected by neighbor's with the application of simple rule. This paper deals with the Cellular Automata in cryptography for a class of Block Ciphers through a new block encryption algorithm based on programmable cellular automata.The proposed algorithm belongs to the class of symmetric key systems. © 2010 Springer-Verlag Berlin Heidelberg.