Sensors, Vol. 19, Pages 1695: Survey on Revocation in Ciphertext-Policy Attribute-Based Encryption (Sensors)

Recently, using advanced cryptographic techniques to process, store, and share datasecurely in an untrusted cloud environment has drawn widespread attention from academicresearchers. In particular, Ciphertext-Policy Attribute-Based Encryption (CP-ABE) is a promising,advanced type of encryption technique that resolves an open challenge to regulate fine-grainedaccess control of sensitive data according to attributes, particularly for Internet of Things (IoT)applications. However, although this technique provides several critical functions such as dataconfidentiality and expressiveness, it faces some hurdles including revocation issues and lack ofmanaging a wide range of attributes. These two issues have been highlighted by many existingstudies due to their complexity which is hard to address without high computational cost affectingthe resource-limited IoT devices. In this paper, unlike other survey papers, existing single andmultiauthority CP-ABE schemes are reviewed with the main focus on their ability to address therevocation issues, the techniques used to manage the revocation, and comparisons among themaccording to a number of secure cloud storage criteria. Therefore, this is the first review paperanalysing the major issues of CP-ABE in the IoT paradigm and explaining the existing approachesto addressing these issues.