A survey on multi-authority and decentralized attribute-based encryption

The introduction of attribute-based encryption (ABE) targets to achieve the implementation of single-to-numerous encryption; however, the sole authority challenge and the issue of distributed management of attributes are bottlenecks to its realization. Multi-authority attribute-based encryption (MA-ABE) where various attribute authorities (which may be independent of each other) control different attribute universe and are involved in the administration of attribute keys for decryption provides the necessary platform to undertake the implementation of fine-grained access regulation over shared data while achieving single-to-numerous encryption. In recent years, research into MA-ABE has seen rapid advancement, and we believe that it is a suitable solution to thwarting the key escrow problem as well as the problem of distributed management of attributes. This paper offers a thorough survey and examines the state-of-the-art of some traditional ABE as well as multi-authority attribute-based encryption schemes over the past decade. Furthermore, the survey gives detailed insights on some essential techniques as well as some classic concretely constructed algorithms. Moreover, we discuss an extension (the different directions) of MA-ABE and its progress since its inception. We also provide design principles of MA-ABE and also show comparisons between existing works on areas as security, performance, and functionality. This paper also discusses several interesting open problems. As far as we can tell, no comparable survey on MA-ABE exists in literature so far.