Objective. The creation and exchange of patients' Electronic Healthcare Records have developed significantly in the last decade. Patients' records are however distributed in data silos across multiple healthcare facilities, posing technical and clinical challenges that may endanger patients' safety. Current healthcare sharing systems ensure interoperability of patients' records across facilities, but they have limits in presenting doctors with the clinical context of the data in the records. We design and implement a platform for managing provenance tracking of Electronic Healthcare Records based on blockchain technology, compliant with the latest healthcare standards and following the patient-informed consent preferences. Methods. The platform leverages two pillars: the use of international standards such as Integrating the Healthcare Enterprise (IHE), Health Level Seven International (HL7)

Abstract. We propose a formal account of XACML, an OASIS standard adhering to the Policy Based Access Control model for the specification and enforcement of access control policies. To clarify all ambiguous and intricate aspects of XACML, we provide it with a more manageable alternative syntax and with a solid semantic ground. This lays the basis for developing tools and methodologies which allow software engineers to easily and precisely regulate access to resources using policies. To demonstrate feasibility and effectiveness of our approach, we provide a software tool, supporting the specification and evaluation of policies and access requests, whose implementation fully relies on our formal development.

Abstract-Access control systems are widely used means for the protection of computing systems. They are defined in terms of access control policies regulating the access to system resources. In this paper, we introduce a formally-defined, fully-implemented framework for specification, analysis and enforcement of attribute-based access control policies. The framework rests on FACPL, a language with a compact, yet expressive, syntax for specification of real-world access control policies and with a rigorously defined denotational semantics. The framework enables the automated verification of properties regarding both the authorisations enforced by single policies and the relationships among multiple policies. Effectiveness and performance of the analysis rely on a semantic-preserving representation of FACPL policies in terms of SMT formulae and on the use of efficient SMT solvers. Our analysis approach explicitly addresses some crucial aspects of policy evaluation, such as missing attributes, erroneous values and obligations, which are instead overlooked in other proposals. The framework is supported by Java-based tools, among which an Eclipse-based IDE offering a tailored development and analysis environment for FACPL policies and a Java library for policy enforcement. We illustrate the framework and its formal ingredients by means of an e-Health case study, while its effectiveness is assessed by means of performance stress tests and experiments on a well-established benchmark.

The importance of the Electronic Health Record (EHR), that stores all healthcare-related data belonging to a patient, has been recognised in recent years by governments, institutions and industry. Initiatives like the Integrating the Healthcare Enterprise (IHE) have been developed for the definition of standard methodologies for secure and interoperable EHR exchanges among clinics and hospitals. Using the requisites specified by these initiatives, many large scale projects have been set up for enabling healthcare professionals to handle patients' EHRs. The success of applications developed in these contexts crucially depends on ensuring such security properties as confidentiality, authentication, and authorization. In this paper, we first propose a communication protocol, based on the IHE specifications, for authenticating healthcare professionals and assuring patients' safety. By means of a formal analysis carried out by using the specification language COWS and the model checker CMC, we reveal a security flaw in the protocol thus demonstrating that to simply adopt the international standards does not guarantee the absence of such type of flaws. We then propose how to emend the IHE specifications and modify the protocol accordingly. Finally, we show how to tailor our protocol for application to more critical scenarios with no assumptions on the communication channels. To demonstrate feasibility and effectiveness of our protocols we have fully implemented them.

The importance of the Electronic Health Record (EHR) has been addressed in recent years by governments and institutions.Many large scale projects have been funded with the aim to allow healthcare professionals to consult patients data. Properties such as confidentiality, authentication and authorization are the key for the success for these projects. The Integrating the Healthcare Enterprise (IHE) initiative promotes the coordinated use of established standards for authenticated and secure EHR exchanges among clinics and hospitals. In particular, the IHE integration profile named XUA permits to attest user identities by relying on SAML assertions, i.e. XML documents containing authentication statements. In this paper, we provide a formal model for the secure issuance of such an assertion. We first specify the scenario using the process calculus COWS and then analyse it using the model checker CMC. Our analysis reveals a potential flaw in the XUA profile when using a SAML assertion in an unprotected network. We then suggest a solution for this flaw, and model check and implement this solution to show that it is secure and feasible