Cryptography is basically securing the data during the communication between different systems. To provide the security of data during communication in cryptography we together require the Algorithm and Key. The confidentiality and integrity of the data during communication depends partially on algorithm and partially on key. Due to human memorizability the size of key in cryptography is limited. 2Dimension graphics image have the property that by visualising or by listening its dimension it is not possible to design exactly the same pattern. In this paper a modified approach is being proposed for increasing the security of the data. For increasing the security we are basically concentrating on the key part of the cryptography we basically uses the 2Dimension graphics image which is designed by the user. 2Dimension Graphics image is composed of pixels in which each pixel have different or same ASCII value. From the large collection of pixel the proposed algorithm will generate any size of key which can be used in encryption as well as in decryption.