Dynamic deployment of context-aware access control policies for constrained security devices

Securing the access to a server, guaranteeing a certain level of protection over an encrypted communication channel, executing particular counter measures when attacks are detected are examples of security requirements. Such requirements are identi ed based on organizational purposes and expectations in terms of resource access and availability and also on system vulnerabilities and threats. All these requirements belong to the so-called security policy. Deploying the policy means enforcing, i.e., con guring, those security components and mechanisms so that the system behavior be nally the one speci ed by the policy. The deployment issue becomes more di cult as the growing organizational requirements and expectations generally leave behind the integration of new security functionalities in the information system: the information system will not always embed the necessary security functionalities for the proper deployment of contextual security requirements. To overcome this issue, our solution is based on a central entity approach which takes in charge unmanaged contextual requirements and dynamically redeploys the policy when context changes are detected by this central entity. We also present an improvement over the OrBAC (Organization-Based Access Control) model. Up to now, a controller based on a contextual OrBAC policy is passive, in the sense that it assumes policy evaluation triggered by access requests. Therefore, it does not allow reasoning about policy state evolution when actions occur. The modi cations introduced by our work overcome this limitation and provide a proactive version of the model by integrating concepts from action speci cation languages

PolyOrBAC: a security framework for critical infrastructures

International audienceDue to physical and logical vulnerabilities, a critical infrastructure (CI) can encounter failures of various degrees of severity, and since there are many interdependencies between CIs, simple failures can have dramatic consequences on the users. In this paper, we mainly focus on malicious threats that might affect the information and communication system that controls the Critical Infrastructure, i.e., the Critical Information Infrastructure (CII). To address the security challenges that are specific of CIIs, we propose a collaborative access control framework called PolyOrBAC. This approach offers each organization taking part in the CII the capacity of collaborating with the other ones, while maintaining a control on its resources and on its internal security policy. The interactions between organizations participating in the CII are implemented through web services (WS), and for each WS a contract is signed between the service-provider organization and the service-user organization. The contract describes the WS functions and parameters, the liability of each party and the security rules controlling the interactions. At runtime, the compliance of all interactions with these security rules is checked. Every deviation from the signed contracts triggers an alarm, the concerned parties are notified and audits can be used as evidence for sanctioning the party responsible for the deviation. Our approach is illustrated by a practical scenario, based on real emergency actions in an electric power grid infrastructure, and a simulation test bed has been implemented to animate this scenario and experiment with its security issues

Self-Protecting Documents for Cloud Storage Security

International audienceInformation security is currently one of the most important issues in information systems. This concerns the confidentiality of information but also its integrity and availability. The problem becomes even more difficult when several companies are working together on a project and that the various documents "go out of" their respective information systems. We propose an architecture in which the documents themselves ensure their security and thus can be exchanged over uncontrolled resources such as cloud storage or even USB flash drives. For this we encapsulate within the document itself some security components (e.g. access control, usage control) to achieve an autonomic document architecture for Enterprise DRM (E-DRM). Using such self-protecting documents, a company can ensure security and privacy for its documents when outsourcing storage services (e.g. cloud)

Context-Based Confidentiality Analysis for Industrial IoT

This dataset contains the models and source code regarding the work described in the paper "Context-Based Confidentiality Analysis for Industrial IoT". To use the content of this dataset, a working setup of the source code and models of the dataset https://zenodo.org/record/2574147#.XoC5KogzZPY, is needed as a base.This dataset is still actively worked on. An updated version might be published in the future. This work was supported by the German Federal Ministry of Education and Research under grant number 01IS17106A (Trust 4.0)

Extracting Role-Based Access Control Models from Business Process Event Logs

Keeruliste äriprotsesside ja järjest suurenevate andmemahtude juures on väljakutsuvaks ülesandeks analüüsida ja parandada ettevõtte äriprotsessi andmeturvalisust. Infosüsteemid, mis toetavad äriprotsessi mudeli (abstraktne esitus äriprotsessist) rakendamist, registreerivad äriprotsessi tegevusi sündmustena eraldi logisse. Salvestatud sündmuste logid on aluseks äriprotsessiga seotud andmete kaevamiseks. Need andmed on vajalikud äriprotsessi analüüsimiseks ja parendamiseks, kuid neid andmeid võib kasutada ka turvaanalüüsiks. Turvaanalüüsi üheks eesmärgiks on ka kontrollida, kas nende andmete hulgas turvalisusega seotud informatsioon on kooskõlas praeguste turvanõuetega. Lisaks, äriprotsessi logide peal saab rakendada äriprotsessikaeve (uurimisvaldkond, mis ühendab andmekaeve ja äriprotsesside modelleerimise) tehnikaid, et luua äriprotsessi mudeleid. Lisaks äriprotsessi mudelitele on võimalik tuletada ka teisi mudeleid, näiteks turvamudeleid, mida saab hiljem kasutada turvameetmete tagamiseks infosüsteemis. Käesoleva töö eesmärgiks on esitada üks võimalik meetod, kuidas luua rollipõhist ligipääsukontrolli esitatavaid turvamudeleid (Role- Based Access Control models) XES-formaadis sündmuste logidest, mis on salvestatud äriprotsessi toetava infosüsteemi poolt. Lisatähelepanu on suunatud kaitstavate infovarade väljaselgitamiseks sündmuste logide põhjal. Need infovarad on näiteks dokumendid, dokumendiväljad, või muud andmed, mida töödeldakse äriprotsessi tegevuste jooksul. Lisaks, me hindame antud meetodi rakendatavust reaalse äriprotsessi sündmuste logi peal. Ühe võimaliku meetodina me kontrollime sündmuste logi andmete ja seoste vastavust juurdepääsu õigustega olemasoleva rollipõhise juurdepääsu kontrolli turvamudelis. Lõppkokkuvõttes võib sündmuste logidest tuletatud rollipõhist ligipääsu kontrolli mudelit võtta aluseks turvaanalüüsiks või rakendada mõnes süsteemis juurdepääsumehhanismina.Today, as business processes are getting more complex and the volumes of stored data about business process executions are increasing in size, collecting information for the analysis and for the improvement of the business process security1, is becoming a complex task. Information systems that support business processes record business process executions into event logs which capture the behavior of system usage in terms of events. Business process event logs can be used for analysing and improving the business process, but also for analysing the information security. One of the main goals of security analysis is to check the compliance with existing security requirements. Also event logs can be the basis for business process mining, or shortly process mining. Utilizing bottom-up process mining on event logs, we can extract business process-related information for security analysis. Process mining is not just only for discovering business process models, but also other models, such as security models. For this purpose, we present a possible approach to extract RBAC models (semi-)automatically from event logs in XES format. The focus is also on determining the protected business assets, such as document or other artifact data that is exchanged and accessed during business process activities. In addition, we evaluate the applicability of this approach with conformance checking where we check the compliance of a real-life event log with respect to the LTL constraints translated from RBAC model. Eventually, the purpose of the extracted RBAC models is that they provide a basis for security analysis and they can be adapted by other applications in order to implement access control mechanism

Context-based confidentiality analysis in dynamic Industry 4.0 scenarios

In Industry 4.0 environments highly dynamic and flexible access control strategies are needed. State of the art strategies are often not included in the modelling process but must be considered afterwards. This makes it very difficult to analyse the security properties of a system. In the framework of the Trust 4.0 project the confidentiality analysis tries to solve this problem using a context-based approach. Thus, there is a security model named context metamodel. Another important problem is that the transformation of an instance of a security model to a wide-spread access control standard is often not possible. This is also the case for the context metamodel. Moreover, another transformation which is very interesting to consider is one to an ensemble based component system which is also presented in the Trust 4.0 project. This thesis introduces an extension to the beforementioned context metamodel in order to add more extensibility to it. Furthermore, the thesis deals with the creation of a concept and an implementation of the transformations mentioned above. For that purpose, at first, the transformation to the attribute-based access control standard XACML is considered. Thereafter, the transformation from XACML to an ensemble based component system is covered. The evaluation indicated that the model can be used for use cases in Industry 4.0 scenarios. Moreover, it also indicated the transformations produce adequately accurate access policies. Furthermore, the scalability evaluation indicated linear runtime behaviour of the implementations of both transformations for respectively higher number of input contexts or XACML rules