Secure access privilege delegation using attribute-based encryption

Attribute-based encryption (ABE) is widely used for a secure and efficient data sharing. The predetermined access policy of ABE shares the data with intended data users. However, ABE is not preferable in many applications that require collaboration among data users. In such applications, an authorized data user may be interested to collaborate with another data user who does not adhere to the access policy. Fixed access policy of ABE does not allow an authorized data user (who satisfies the access policy) to collaborate or share the data with any unauthorized data user (who fails to satisfy the access policy). Thus, due to the static and predefined access policy, data collaboration in ABE is significantly challenging. In this work, we attempt to address this important issue of ABE through proxy re-encryption mechanism. We have formally proved the security of our proposed system. Moreover, we have demonstrated that the proposed system permits revocation of delegation rights.