Minimization of Cipher Text Size and KAC for Data Sharing in Cloud

Cloud computing are the delivery of hosted services over the internet. Due to various data leakages the data owner encrypts the files before uploading to the cloud storage. Data user need to decrypt the files so request has been sent to data owner. The data owner sends the single aggregate decryption key for the data user. The aggregate decryption key helps to decrypt the files. This compact single key can be conveniently sent to data users so that multiple key costs can be saved. The problem here is the size of cipher text stored in cloud is large. The number of cipher text grows rapidly in cloud system. So we have to save space for future extension. In the proposed system, the size of cipher text is minimized using UTF-8 bit character encoding. It helps to reduce the large size of cipher text stored in cloud space.