Visible to the public Biblio

Filters: Keyword is Security Policies Analysis  [Clear All Filters]
2019-10-22
Hagan, Matthew, Siddiqui, Fahad, Sezer, Sakir.  2018.  Policy-Based Security Modelling and Enforcement Approach for Emerging Embedded Architectures. 2018 31st IEEE International System-on-Chip Conference (SOCC). :84–89.
Complex embedded systems often contain hard to find vulnerabilities which, when exploited, have potential to cause severe damage to the operating environment and the user. Given that threats and vulnerabilities can exist within any layer of the complex eco-system, OEMs face a major challenge to ensure security throughout the device life-cycle To lower the potential risk and damage that vulnerabilities may cause, OEMs typically perform application threat analysis and security modelling. This process typically provides a high level guideline to solving security problems which can then be implemented during design and development. However, this concept presents issues where new threats or unknown vulnerability has been discovered. To address this issue, we propose a policy-based security modelling approach, which utilises a configurable policy engine to apply new policies that counter serious threats. By utilising this approach, the traditional security modelling approaches can be enhanced and the consequences of a new threat greatly reduced. We present a realistic use case of connected car, applying several attack scenarios. By utilising STRIDE threat modelling and DREAD risk assessment model, adequate policies are derived to protect the car assets. This approach poses advantages over the standard approach, allowing a policy update to counter a new threat, which may have otherwise required a product redesign to alleviate the issue under the traditional approach.
Deb Nath, Atul Prasad, Bhunia, Swarup, Ray, Sandip.  2018.  ArtiFact: Architecture and CAD Flow for Efficient Formal Verification of SoC Security Policies. 2018 IEEE Computer Society Annual Symposium on VLSI (ISVLSI). :411–416.
Verification of security policies represents one of the most critical, complex, and expensive steps of modern SoC design validation. SoC security policies are typically implemented as part of functional design flow, with a diverse set of protection mechanisms sprinkled across various IP blocks. An obvious upshot is that their verification requires comprehension and analysis of the entire system, representing a scalability bottleneck for verification tools. The scale and complexity of industrial SoC is far beyond the analysis capacity of state-of-the-art formal tools; even simulation-based security verification is severely limited in effectiveness because of the need to exercise subtle corner-cases across the entire system. We address this challenge by developing a novel security architecture that accounts for verification needs from the ground up. Our framework, ArtiFact, provides an alternative architecture for security policy implementation that exploits a flexible, centralized, infrastructure IP and enables scalable, streamlined verification of these policies. With our architecture, verification of system-level security policies reduces to analysis of this single IP and its interfaces, enabling off-the-shelf formal tools to successfully verify these policies. We introduce a CAD flow that supports both formal and dynamic (simulation-based) verification, and is built on top of such off-the-shelf tools. Our approach reduces verification time by over 62X and bug detection time by 34X for illustrative policies.
Alzahrani, Ahmed, Johnson, Chris, Altamimi, Saad.  2018.  Information security policy compliance: Investigating the role of intrinsic motivation towards policy compliance in the organisation. 2018 4th International Conference on Information Management (ICIM). :125–132.
Recent behavioral research in information security has focused on increasing employees' motivation to enhance the security performance in an organization. This empirical study investigated employees' information security policy (ISP) compliance intentions using self-determination theory (SDT). Relevant hypotheses were developed to test the proposed research model. Data obtained via a survey (N=3D407) from a Fortune 600 organization in Saudi Arabia provides empirical support for the model. The results confirmed that autonomy, competence and the concept of relatedness all positively affect employees' intentions to comply. The variable 'perceived value congruence' had a negative effect on ISP compliance intentions, and the perceived legitimacy construct did not affect employees' intentions. In general, the findings of this study suggest that SDT has value in research into employees' ISP compliance intentions.
Khelf, Roumaissa, Ghoualmi-Zine, Nacira.  2018.  IPsec/Firewall Security Policy Analysis: A Survey. 2018 International Conference on Signal, Image, Vision and their Applications (SIVA). :1–7.
As the technology reliance increases, computer networks are getting bigger and larger and so are threats and attacks. Therefore Network security becomes a major concern during this last decade. Network Security requires a combination of hardware devices and software applications. Namely, Firewalls and IPsec gateways are two technologies that provide network security protection and repose on security policies which are maintained to ensure traffic control and network safety. Nevertheless, security policy misconfigurations and inconsistency between the policy's rules produce errors and conflicts, which are often very hard to detect and consequently cause security holes and compromise the entire system functionality. In This paper, we review the related approaches which have been proposed for security policy management along with surveying the literature for conflicts detection and resolution techniques. This work highlights the advantages and limitations of the proposed solutions for security policy verification in IPsec and Firewalls and gives an overall comparison and classification of the existing approaches.
Li, Ling, An, Xiaoguang.  2018.  Research on Storage Mechanism of Cloud Security Policy. 2018 International Conference on Virtual Reality and Intelligent Systems (ICVRIS). :130–133.
Cloud computing, cloud security and cloud storage have been gradually introduced into people's life and become hot topicsof research, for which relevant technologies have permeated through the computer industry and relevant industries. With the coming of the modern information society, secure storage of data has been becoming increasingly important. Proceeding from traditional policy storage, this paper includes comparison and improvement of policy storage for the purpose of meeting requirements of storage of cloud security policy. Policy storage technology refers to a technology used to realize storage of policies created by users and relevant policy information. Policy repository can conduct centralized management and processing of multiple policies and their relevant information. At present, popular policy repositories generally include policy storage for relational database or policy storage for directory server or a file in a fixed format, such as XML file format.
2019-06-17
Martinelli, Fabio, Michailidou, Christina, Mori, Paolo, Saracino, Andrea.  2018.  Too Long, Did Not Enforce: A Qualitative Hierarchical Risk-Aware Data Usage Control Model for Complex Policies in Distributed Environments. Proceedings of the 4th ACM Workshop on Cyber-Physical System Security. :27–37.

Distributed environments such as Internet of Things, have an increasing need of introducing access and usage control mechanisms, to manage the rights to perform specific operations and regulate the access to the plethora of information daily generated by these devices. Defining policies which are specific to these distributed environments could be a challenging and tedious task, mainly due to the large set of attributes that should be considered, hence the upcoming of unforeseen conflicts or unconsidered conditions. In this paper we propose a qualitative risk-based usage control model, aimed at enabling a framework where is possible to define and enforce policies at different levels of granularity. In particular, the proposed framework exploits the Analytic Hierarchy Process (AHP) to coalesce the risk value assigned to different attributes in relation to a specific operation, in a single risk value, to be used as unique attribute of usage control policies. Two sets of experiments that show the benefits both in policy definition and in performance, validate the proposed model, demonstrating the equivalence of enforcement among standard policies and the derived single-attributed policies.

Zheng, Jianjun, Siami Namin, Akbar.  2018.  A Markov Decision Process to Determine Optimal Policies in Moving Target. Proceedings of the 2018 ACM SIGSAC Conference on Computer and Communications Security. :2321–2323.

Moving Target Defense (MTD) has been introduced as a new game changer strategy in cybersecurity to strengthen defenders and conversely weaken adversaries. The successful implementation of an MTD system can be influenced by several factors including the effectiveness of the employed technique, the deployment strategy, the cost of the MTD implementation, and the impact from the enforced security policies. Several efforts have been spent on introducing various forms of MTD techniques. However, insufficient research work has been conducted on cost and policy analysis and more importantly the selection of these policies in an MTD-based setting. This poster paper proposes a Markov Decision Process (MDP) modeling-based approach to analyze security policies and further select optimal policies for moving target defense implementation and deployment. The adapted value iteration method would solve the Bellman Optimality Equation for optimal policy selection for each state of the system. The results of some simulations indicate that such modeling can be used to analyze the impact of costs of possible actions towards the optimal policies.

2019-03-28
Fernández, Maribel, Jaimunk, Jenjira, Thuraisingham, Bhavani.  2018.  Graph-Based Data-Collection Policies for the Internet of Things. Proceedings of the 4th Annual Industrial Control System Security Workshop. :9-16.

Smart industrial control systems (e.g., smart grid, oil and gas systems, transportation systems) are connected to the internet, and have the capability to collect and transmit data; as such, they are part of the IoT. The data collected can be used to improve services; however, there are serious privacy risks. This concern is usually addressed by means of privacy policies, but it is often difficult to understand the scope and consequences of such policies. Better tools to visualise and analyse data collection policies are needed. Graph-based modelling tools have been used to analyse complex systems in other domains. In this paper, we apply this technique to IoT data-collection policy analysis and visualisation. We describe graphical representations of category-based data collection policies and show that a graph-based policy language is a powerful tool not only to specify and visualise the policy, but also to analyse policy properties. We illustrate the approach with a simple example in the context of a chemical plant with a truck monitoring system. We also consider policy administration: we propose a classification of queries to help administrators analyse policies, and we show how the queries can be answered using our technique.

2019-02-18
Fukushima, Keishiro, Nakamura, Toru, Ikeda, Daisuke, Kiyomoto, Shinsaku.  2018.  Challenges in Classifying Privacy Policies by Machine Learning with Word-based Features. Proceedings of the 2Nd International Conference on Cryptography, Security and Privacy. :62–66.

In this paper, we discuss challenges when we try to automatically classify privacy policies using machine learning with words as the features. Since it is difficult for general public to understand privacy policies, it is necessary to support them to do that. To this end, the authors believe that machine learning is one of the promising ways because users can grasp the meaning of policies through outputs by a machine learning algorithm. Our final goal is to develop a system which automatically translates privacy policies into privacy labels [1]. Toward this goal, we classify sentences in privacy policies with category labels, using popular machine learning algorithms, such as a naive Bayes classifier.We choose these algorithms because we could use trained classifiers to evaluate keywords appropriate for privacy labels. Therefore, we adopt words as the features of those algorithms. Experimental results show about 85% accuracy. We think that much higher accuracy is necessary to achieve our final goal. By changing learning settings, we identified one reason of low accuracies such that privacy policies include many sentences which are not direct description of information about categories. It seems that such sentences are redundant but maybe they are essential in case of legal documents in order to prevent misinterpreting. Thus, it is important for machine learning algorithms to handle these redundant sentences appropriately.

2017-12-12
Lu, Y., Sheng, W., Riliang, L., Jin, P..  2017.  Research and Construction of Dynamic Awareness Security Protection Model Based on Security Policy. 2017 IEEE International Conference on Smart Cloud (SmartCloud). :202–207.

In order to ensure the security of electric power supervisory control and data acquisition (SCADA) system, this paper proposes a dynamic awareness security protection model based on security policy, the design idea of which regards safety construction protection as a dynamic analysis process and the security policy should adapt to the network dynamics. According to the current situation of the power SCADA system, the related security technology and the investigation results of system security threat, the paper analyzes the security requirements and puts forward the construction ideas of security protection based on policy protection detection response (P2DR) policy model. The dynamic awareness security protection model proposed in this paper is an effective and useful tool for protecting the security of power-SCADA system.

Fernando, R., Ranchal, R., Bhargava, B., Angin, P..  2017.  A Monitoring Approach for Policy Enforcement in Cloud Services. 2017 IEEE 10th International Conference on Cloud Computing (CLOUD). :600–607.

When clients interact with a cloud-based service, they expect certain levels of quality of service guarantees. These are expressed as security and privacy policies, interaction authorization policies, and service performance policies among others. The main security challenge in a cloud-based service environment, typically modeled using service-oriented architecture (SOA), is that it is difficult to trust all services in a service composition. In addition, the details of the services involved in an end-to-end service invocation chain are usually not exposed to the clients. The complexity of the SOA services and multi-tenancy in the cloud environment leads to a large attack surface. In this paper we propose a novel approach for end-to-end security and privacy in cloud-based service orchestrations, which uses a service activity monitor to audit activities of services in a domain. The service monitor intercepts interactions between a client and services, as well as among services, and provides a pluggable interface for different modules to analyze service interactions and make dynamic decisions based on security policies defined over the service domain. Experiments with a real-world service composition scenario demonstrate that the overhead of monitoring is acceptable for real-time operation of Web services.

Contreras, G. K., Nahiyan, A., Bhunia, S., Forte, D., Tehranipoor, M..  2017.  Security vulnerability analysis of design-for-test exploits for asset protection in SoCs. 2017 22nd Asia and South Pacific Design Automation Conference (ASP-DAC). :617–622.

SoCs implementing security modules should be both testable and secure. Oversights in a design's test structure could expose internal modules creating security vulnerabilities during test. In this paper, for the first time, we propose a novel automated security vulnerability analysis framework to identify violations of confidentiality, integrity, and availability policies caused by test structures and designer oversights during SoC integration. Results demonstrate existing information leakage vulnerabilities in implementations of various encryption algorithms and secure microprocessors. These can be exploited to obtain secret keys, control finite state machines, or gain unauthorized access to memory read/write functions.

Zhu, G., Zeng, Y., Guo, M..  2017.  A Security Analysis Method for Supercomputing Users \#x2019; Behavior. 2017 IEEE 4th International Conference on Cyber Security and Cloud Computing (CSCloud). :287–293.

Supercomputers are widely applied in various domains, which have advantage of high processing capability and mass storage. With growing supercomputing users, the system security receives comprehensive attentions, and becomes more and more important. In this paper, according to the characteristics of supercomputing environment, we perform an in-depth analysis of existing security problems in the process of using resources. To solve these problems, we propose a security analysis method and a prototype system for supercomputing users' behavior. The basic idea is to restore the complete users' behavior paths and operation records based on the supercomputing business process and track the use of resources. Finally, the method is evaluated and the results show that the security analysis method of users' behavior can help administrators detect security incidents in time and respond quickly. The final purpose is to optimize and improve the security level of the whole system.

Durante, L., Seno, L., Valenza, F., Valenzano, A..  2017.  A model for the analysis of security policies in service function chains. 2017 IEEE Conference on Network Softwarization (NetSoft). :1–6.

Two emerging architectural paradigms, i.e., Software Defined Networking (SDN) and Network Function Virtualization (NFV), enable the deployment and management of Service Function Chains (SFCs). A SFC is an ordered sequence of abstract Service Functions (SFs), e.g., firewalls, VPN-gateways, traffic monitors, that packets have to traverse in the route from source to destination. While this appealing solution offers significant advantages in terms of flexibility, it also introduces new challenges such as the correct configuration and ordering of SFs in the chain to satisfy overall security requirements. This paper presents a formal model conceived to enable the verification of correct policy enforcements in SFCs. Software tools based on the model can then be designed to cope with unwanted network behaviors (e.g., security flaws) deriving from incorrect interactions of SFs of the same SFC. 

Rezaeibagha, F., Mu, Y..  2017.  Access Control Policy Combination from Similarity Analysis for Secure Privacy-Preserved EHR Systems. 2017 IEEE Trustcom/BigDataSE/ICESS. :386–393.

In distributed systems, there is often a need to combine the heterogeneous access control policies to offer more comprehensive services to users in the local or national level. A large scale healthcare system is usually distributed in a computer network and might require sophisticated access control policies to protect the system. Therefore, the need for integrating the electronic healthcare systems might be important to provide a comprehensive care for patients while preserving patients' privacy and data security. However, there are major impediments in healthcare systems concerning not well-defined and flexible access control policy implementations, hindering the progress towards secure integrated systems. In this paper, we introduce an access control policy combination framework for EHR systems that preserves patients' privacy and ensures data security. We achieve our goal through an access control mechanism which handles multiple access control policies through a similarity analysis phase. In that phase, we evaluate different XACML policies to decide whether or not a policy combination is applicable. We have provided a case study to show the applicability of our proposed approach based on XACML. Our study results can be applied to the electronic health record (EHR) access control policy, which fosters interoperability and scalability among healthcare providers while preserving patients' privacy and data security. 

Zhang, M., Chen, Q., Zhang, Y., Liu, X., Dong, S..  2017.  Requirement analysis and descriptive specification for exploratory evaluation of information system security protection capability. 2017 IEEE 2nd Advanced Information Technology, Electronic and Automation Control Conference (IAEAC). :1874–1878.

Exploratory evaluation is an effective way to analyze and improve the security of information system. The information system structure model for security protection capability is set up in view of the exploratory evaluation requirements of security protection capability, and the requirements of agility, traceability and interpretation for exploratory evaluation are obtained by analyzing the relationship between information system, protective equipment and protection policy. Aimed at the exploratory evaluation description problem of security protection capability, the exploratory evaluation problem and exploratory evaluation process are described based on the Granular Computing theory, and a general mathematical description is established. Analysis shows that the standardized description established meets the exploratory evaluation requirements, and it can provide an analysis basis and description specification for exploratory evaluation of information system security protection capability.

Bijoy, J. M., Kavitha, V. K., Radhakrishnan, B., Suresh, L. P..  2017.  A Graphical Password Authentication for analyzing legitimate user in online social network and secure social image repository with metadata. 2017 International Conference on Circuit ,Power and Computing Technologies (ICCPCT). :1–7.

Internet plays a crucial role in today's life, so the usage of online social network monotonically increasing. People can share multimedia information's fastly and keep in touch or communicate with friend's easily through online social network across the world. Security in authentication is a big challenge in online social network and authentication is a preliminary process for identifying legitimate user. Conventionally, we are using alphanumeric textbased password for authentication approach. But the main flaw points of text based password is highly vulnerable to attacks and difficulty of recalling password during authentication time due to the irregular use of passwords. To overcome the shortcoming of text passwords, we propose a Graphical Password authentication. An approach of Graphical Password is an authentication of amalgam of pictures. It is less vulnerable to attacks and human can easily recall pictures better than text. So the graphical password is a better alternative to text passwords. As the image uploads are increasing by users share through online site, privacy preserving has become a major problem. So we need a Caption Based Metadata Stratification of images for delivers an automatic suggestion of similar category already in database, it works by comparing the caption metadata of album with caption metadata already in database or extract the synonyms of caption metadata of new album for checking the similarity with caption metadata already in database. This stratification offers an enhanced automatic privacy prediction for uploaded images in online social network, privacy is an inevitable factor for uploaded images, and privacy violation is a major concern. So we propose an Automatic Policy Prediction for uploaded images that are classified by caption metadata. An automatic policy prediction is a hassle-free privacy setting proposed to the user.

Alcorn, J., Melton, S., Chow, C. E..  2017.  SDN data path confidence analysis. 2017 IEEE Conference on Dependable and Secure Computing. :209–216.

The unauthorized access or theft of sensitive, personal information is becoming a weekly news item. The illegal dissemination of proprietary information to media outlets or competitors costs industry untold millions in remediation costs and losses every year. The 2013 data breach at Target, Inc. that impacted 70 million customers is estimated to cost upwards of 1 billion dollars. Stolen information is also being used to damage political figures and adversely influence foreign and domestic policy. In this paper, we offer some techniques for better understanding the health and security of our networks. This understanding will help professionals to identify network behavior, anomalies and other latent, systematic issues in their networks. Software-Defined Networks (SDN) enable the collection of network operation and configuration metrics that are not readily available, if available at all, in traditional networks. SDN also enables the development of software protocols and tools that increases visibility into the network. By accumulating and analyzing a time series data repository (TSDR) of SDN and traditional metrics along with data gathered from our tools we can establish behavior and security patterns for SDN and SDN hybrid networks. Our research helps provide a framework for a range of techniques for administrators and automated system protection services that give insight into the health and security of the network. To narrow the scope of our research, this paper focuses on a subset of those techniques as they apply to the confidence analysis of a specific network path at the time of use or inspection. This confidence analysis allows users, administrators and autonomous systems to decide whether a network path is secure enough for sending their sensitive information. Our testing shows that malicious activity can be identified quickly as a single metric indicator and consistently within a multi-factor indicator analysis. Our research includes the implementation of - hese techniques in a network path confidence analysis service, called Confidence Assessment as a Service. Using our behavior and security patterns, this service evaluates a specific network path and provides a confidence score for that path before, during and after the transmission of sensitive data. Our research and tools give administrators and autonomous systems a much better understanding of the internal operation and configuration of their networks. Our framework will also provide other services that will focus on detecting latent, systemic network problems. By providing a better understanding of network configuration and operation our research enables a more secure and dependable network and helps prevent the theft of information by malicious actors.

Hellmann, B., Ahlers, V., Rodosek, G. D..  2017.  Integrating visual analysis of network security and management of detection system configurations. 2017 9th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (IDAACS). 2:1020–1025.

A problem in managing the ever growing computer networks nowadays is the analysis of events detected by intrusion detection systems and the classification whether an event was correctly detected or not. When a false positive is detected by the user, changes to the configuration must be made and evaluated before they can be adopted to productive use. This paper describes an approach for a visual analysis framework that integrates the monitoring and analysis of events and the resulting changes on the configuration of detection systems after finding false alarms, together with a preliminary simulation and evaluation of the changes.

2017-09-26
Fernández, Maribel, Kantarcioglu, Murat, Thuraisingham, Bhavani.  2016.  A Framework for Secure Data Collection and Management for Internet of Things. Proceedings of the 2Nd Annual Industrial Control System Security Workshop. :30–37.

More and more current industrial control systems (e.g, smart grids, oil and gas systems, connected cars and trucks) have the capability to collect and transmit users' data in order to provide services that are tailored to the specific needs of the customers. Such smart industrial control systems fall into the category of Internet of Things (IoT). However, in many cases, the data transmitted by such IoT devices includes sensitive information and users are faced with an all-or-nothing choice: either they adopt the proposed services and release their private data, or refrain from using services which could be beneficial but pose significant privacy risks. Unfortunately, encryption alone does not solve the problem, though techniques to counter these privacy risks are emerging (e.g., by using applications that alter, merge or bundle data to ensure they cannot be linked to a particular user). In this paper, we propose a general framework, whereby users can not only specify how their data is managed, but also restrict data collection from their connected devices. More precisely, we propose to use data collection policies to govern the transmission of data from IoT devices, coupled with policies to ensure that once the data has been transmitted, it is stored and shared in a secure way. To achieve this goal, we have designed a framework for secure data collection, storage and management, with logical foundations that enable verification of policy properties.

Konigsmark, S. T. Choden, Chen, Deming, Wong, Martin D. F..  2016.  Information Dispersion for Trojan Defense Through High-level Synthesis. Proceedings of the 53rd Annual Design Automation Conference. :87:1–87:6.

Emerging technologies such as the Internet of Things (IoT) heavily rely on hardware security for data and privacy protection. However, constantly increasing integration complexity requires automatic synthesis to maintain the pace of innovation. We introduce the first High-Level Synthesis (HLS) flow that produces a security enhanced hardware design to directly prevent Hardware Trojan Horse (HTH) injection by a malicious foundry. Through analysis of entropy loss and criticality decay, the presented algorithms implement highly efficient resource-targeted information dispersion to counter HTH insertion. The flow is evaluated on existing HLS benchmarks and a new IoT-specific benchmark and shows significant resource savings.

Bertolino, Antonia, Daoudagh, Said, Lonetti, Francesca, Marchetti, Eda.  2016.  Testing Access Control Policies Against Intended Access Rights. Proceedings of the 31st Annual ACM Symposium on Applied Computing. :1641–1647.

Access Control Policies are used to specify who can access which resource under which conditions, and ensuring their correctness is vital to prevent security breaches. As access control policies can be complex and error-prone, we propose an original framework that supports the validation of the implemented policies (specified in the standard XACML notation) against the intended rights, which can be informally expressed, e.g. in tabular form. The framework relies on well-known software testing technology, such as mutation and combinatorial techniques. The paper presents the implemented environment and an application example.

Bertolissi, Clara, Talbot, Jean-Marc, Villevalois, Didier.  2016.  Analysis of Access Control Policy Updates Through Narrowing. Proceedings of the 18th International Symposium on Principles and Practice of Declarative Programming. :62–75.

Administration of access control policies is a difficult task, especially in large organizations. We consider the problem of detecting whether administrative actions can yield in policies where some security goals are compromised. In particular, we are interested in problems generated by modifications –- such as adding/deleting elements to/from the set of possible users or permissions –- of policies specified as term-rewrite systems. We propose to use rewriting techniques to compare the behaviors of the modified version and the original version of the policy. More precisely, we use narrowing to compute counter-examples to the equivalence of rewrite-based policies. We prove that our technique provides a sound and complete way to recursively enumerate the set of counter-examples, even when this set is not finite, or when a mistake of the administrator makes one or both systems non-terminating.

St-Martin, Michel, Felty, Amy P..  2016.  A Verified Algorithm for Detecting Conflicts in XACML Access Control Rules. Proceedings of the 5th ACM SIGPLAN Conference on Certified Programs and Proofs. :166–175.

We describe the formalization of a correctness proof for a conflict detection algorithm for XACML (eXtensible Access Control Markup Language). XACML is a standardized declarative access control policy language that is increasingly used in industry. In practice it is common for rule sets to grow large, and contain unintended errors, often due to conflicting rules. A conflict occurs in a policy when one rule permits a request and another denies that same request. Such errors can lead to serious risks involving both allowing access to an unauthorized user as well as denying access to someone who needs it. Removing conflicts is thus an important aspect of debugging policies, and the use of a verified algorithm provides the highest assurance in a domain where security is important. In this paper, we focus on several complex XACML constructs, including time ranges and integer intervals, as well as ways to combine any number of functions using the boolean operators and, or, and not. The latter are the most complex, and add significant expressive power to the language. We propose an algorithm to find conflicts and then use the Coq Proof Assistant to prove the algorithm correct. We develop a library of tactics to help automate the proof.

Benton, Kevin, Camp, L. Jean.  2016.  Firewalling Scenic Routes: Preventing Data Exfiltration via Political and Geographic Routing Policies. Proceedings of the 2016 ACM Workshop on Automated Decision Making for Active Cyber Defense. :31–36.

In this paper we describe a system that allows the real time creation of firewall rules in response to geographic and political changes in the control-plane. This allows an organization to mitigate data exfiltration threats by analyzing Border Gateway Protocol (BGP) updates and blocking packets from being routed through problematic jurisdictions. By inspecting the autonomous system paths and referencing external data sources about the autonomous systems, a BGP participant can infer the countries that traffic to a particular destination address will traverse. Based on this information, an organization can then define constraints on its egress traffic to prevent sensitive data from being sent via an untrusted region. In light of the many route leaks and BGP hijacks that occur today, this offers a new option to organizations willing to accept reduced availability over the risk to confidentiality. Similar to firewalls that allow organizations to block traffic originating from specific countries, our approach allows blocking outbound traffic from transiting specific jurisdictions. To illustrate the efficacy of this approach, we provide an analysis of paths to various financial services IP addresses over the course of a month from a single BGP vantage point that quantifies the frequency of path alterations resulting in the traversal of new countries. We conclude with an argument for the utility of country-based egress policies that do not require the cooperation of upstream providers.