In Attribute-Based Encryption (ABE) scheme, attributes play a crucial role. Attributes have been utilized to generate a public key for encrypting data and have been used as an access policy to control users' access. The access policy can be divided as either key-policy or cipher text-policy. The key-policy is the access structure on the user's private key, and the cipher text-policy is the access structure on the cipher text. And the access structure can also be further divided as either monotonic or non-monotonic one. Using ABE schemes one can have the advantages: to reduce the communication overhead of the Internet, and to provide fine-grained access control.