@article {Ayache2016189,
	title = {Analysis and verification of XACML policies in a medical cloud environment},
	journal = {Scalable Computing},
	volume = {17},
	number = {3},
	year = {2016},
	note = {cited By 2},
	pages = {189-205},
	abstract = {The connectivity of devices, machines and people via Cloud infrastructure can support collaborations among doctors and specialists from different medical organisations. Such collaborations may lead to data sharing and joint tasks and activities. Hence, the collaborating organisations are responsible for managing and protecting data they share. Therefore, they should define a set of access control policies regulating the exchange of data they own. However, existing Cloud services do not offer tools to analyse these policies. In this paper, we propose a Cloud Policy Verification Service (CPVS) for the analysis and the verification of access control policies specified using XACML. The analysis process detects anomalies at two policy levels: a) intra-policy: detects discrepancies between rules within a single security policy (conflicting rules and redundancies), and b) interpolicies: detects anomalies between several security policies such as inconsistency and similarity. The verification process consists in verifying the completeness property which guarantees that each access request is either accepted or denied by the access control policy. In order to demonstrate the efficiency of our method, we also provide the time and space complexities. Finally, we present the implementation of our method and demonstrate how efficiently our approach can detect policy anomalies. {\textcopyright} 2016 SCPE.},
	doi = {10.12694/scpe.v17i3.1180},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84986332574\&doi=10.12694\%2fscpe.v17i3.1180\&partnerID=40\&md5=86b782c01a2231027ed2e7308e178385},
	author = {Ayache, M.a and Erradi, M.a and Khoumsi, A.b and Freisleben, B.c}
}
@conference {Krombi2014306,
	title = {Automata-based approach to design and analyze security policies},
	booktitle = {2014 12th Annual Conference on Privacy, Security and Trust, PST 2014},
	year = {2014},
	note = {cited By 2},
	pages = {306-313},
	abstract = {Information systems must be controlled by security policies to protect them from undue accesses. Security policies are often designed by rules expressed using informal text, which implies ambiguities and inconsistencies in security rules. Our objective in this paper is to develop a formal approach to design and analyze security policies. We propose a procedure that synthesizes an automaton which implements a given security policy. Our automata-based approach can be a common basis to analyze several aspects of security policies. We use our automata-based approach to develop three analysis procedures to: verify completeness of a security policy, detect anomalies in a security policy, and detect functional discrepancies between several implementations of a security policy. We illustrate our approach using examples of security policies for a firewall. {\textcopyright} 2014 IEEE.},
	doi = {10.1109/PST.2014.6890953},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84910095793\&doi=10.1109\%2fPST.2014.6890953\&partnerID=40\&md5=c203c3363442208f90fb65f844c4a72b},
	author = {Krombi, W.a and Erradi, M.a and Khoumsi, A.b}
}
