The ISC International Journal of Information Security

Abstract Android is a widely used operating system that employs a permission-based access control model. The Android Permissions System (APS) is responsible for mediating application resource requests. APS is a critical component of the Android security mechanism; hence, a failure in the design of APS can potentially lead to vulnerabilities that grant unauthorized access to resources by malicious applications. In this paper, we present a formal approach for modeling and verifying the security properties of APS. We demonstrate the usability of the proposed approach by showcasing the detection of a well-known
vulnerability found in Android’s custom permissions.

Abstract In this paper, we shortly review two formal approaches in verification of security protocols; model checking and theorem proving. Model checking is based on studying the behavior of protocols via generating all different behaviors of a protocol and checking whether the desired goals are satisfied in all instances or not. We investigate Scyther operational semantics as n example of this approach and then we model and verify some famous security protocols using Scyther. Theorem proving is based on deriving the desired goals from assumption of protocols via a deduction system. We define a deduction system named Simple Logic for Authentication to formally define the notion of authenticated communication based on the structure of the messages, and then we several famous protocols using our proposed deduction system and compare it with the verification results of Scyther model checking.

Abstract Despite significant advances in the access control domain, requirements of new computational environments like web services still raise new challenges. Lack of appropriate method for specification of access control policies (ACPs), composition, verification and analysis of them have all made the access control in the composition of web services a complicated problem. In this paper, a new independent formal model called Constrained Policy Graph (CPG) for specification of ACPs and their composition as well as verification of conflict or incompatibility among the ACPs is represented. It is shown how CPG can be used in modeling and verification of web service composition ACPs. Also the application of CPG for modeling policies in BPEL processes -as the most common composition method for web services- is illustrated.