ABSTRACT
The traditional approach of public key cryptography includes the encryption of the messages for the particular receiver by using his/her public key. In 2006, Vipul Goyal introduces the Key-policy (KP)-attribute-based encryption (ABE) scheme. In this scheme, the encrypted data are attached with the set of descriptive attributes, and it also forms end user’s private key access policy. In the KP-ABE scheme, the problem that the data owner fails to decide is who is the user and who will decrypt the encrypted message. Limitations that CP-ABE scheme faces are in terms of organizing user attributes and defining policies and decryption keys only support logically specified a single set of user attributes. In ABE, the public key and the master key are according to the set of attributes and are pre-defined, and if the user-predefined attributes don’t match, the authority re-generates the master key and the public key.
