Notation

Description

Group’s ID

Group public key and master key

Group public key component for attribute a

Group master key component for attribute a

The access structure of user

Attributes associated with leaf nodes of pol

Secret key of the user

User secret key component for attribute a

Group attributes set

File attributes set

Group attribute history list for attribute a

File’s ID

The virtual attribute

Ciphertext and the ciphertext component for attribute a

Symmetric data encryption key of a data file

Group user list

Signature of data owner on message m

Proxy re-encryption key the current attribute a to the updated version a’

The system users list