2016/02/29 by William C. Garrison, Adam Shull, Garrison, William C. +6
Computer Science · Social Sciences · #Access Control and Trust #Cloud Data Security Solutions #Cryptography and Data Security #Cryptography and Security (cs.CR) #FOS: Computer and information sciences
paper · pdf · doi:10.48550/arxiv.1602.09069
openalex publication_date 2016/02/29 · openalex created_date 2022/09/30 · openalex updated_date 2026/07/28
The ability to enforce robust and dynamic access controls on cloud-hosted\ndata while simultaneously ensuring confidentiality with respect to the cloud\nitself is a clear goal for many users and organizations. To this end, there has\nbeen much cryptographic research proposing the use of (hierarchical)\nidentity-based encryption, attribute-based encryption, predicate encryption,\nfunctional encryption, and related technologies to perform robust and private\naccess control on untrusted cloud providers. However, the vast majority of this\nwork studies static models in which the access control policies being enforced\ndo not change over time. This is contrary to the needs of most practical\napplications, which leverage dynamic data and/or policies. In this paper, we\nshow that the cryptographic enforcement of dynamic access controls on untrusted\nplatforms incurs computational costs that are likely prohibitive in practice.\nSpecifically, we develop lightweight constructions for enforcing role-based\naccess controls (i.e., \RBAC0) over cloud-hosted files using\nidentity-based and traditional public-key cryptography. This is done under a\nthreat model as close as possible to the one assumed in the cryptographic\nliterature. We prove the correctness of these constructions, and leverage\nreal-world \RBAC datasets and recent techniques developed by the\naccess control community to experimentally analyze, via simulation, their\nassociated computational costs. This analysis shows that supporting revocation,\nfile updates, and other state change functionality is likely to incur\nprohibitive overheads in even minimally-dynamic, realistic scenarios. We\nidentify a number of bottlenecks in such systems, and fruitful areas for future\nwork that will lead to more natural and efficient constructions for the\ncryptographic enforcement of dynamic access controls.\n