Attribute-Based Encryption is a type of public-key encryption in which the key used for encryption is based on selected attributes of the readers. Decryption of the ciphertext is possible only if the set of attributes of the user includes all the attributes used to encrypt the ciphertext.
On top there is a trusted authority, then domain authority and users. The trusted authority has public key and master key. The domain authority has one master key and the users have a secret key. On ...