Biblio

In this paper, we propose an access control model featured with the efficient key update function in data outsourcing environment. Our access control is based on the combination of Ciphertext Policy - Attribute-based Encryption (CP-ABE) and Role-based Access Control (RBAC). The proposed scheme aims to improve the attribute and key update management of the original CP-ABE. In our scheme, a user's key is incorporated into the attribute certificate (AC) which will be used to decrypt the ciphertext encrypted with CP-ABE policy. If there is any change (update or revoke) of the attributes appearing in the key, the key in the AC will be updated upon the access request. This significantly reduces the overheads in updating and distributing keys of all users simultaneously compared to the existing CP-ABE based schemes. Finally, we conduct the experiment to evaluate the performance of our proposed scheme to show the efficiency of our proposed scheme.

Role-Based Access Control (RBAC) is often used in web applications to restrict operations and protect security sensitive information and resources. Web applications regularly undergo maintenance and evolution and their security may be affected by source code changes between releases. To prevent security regression and vulnerabilities, developers have to take re-validation actions before deploying new releases. This may become a significant undertaking, especially when quick and repeated releases are sought. We define protection-impacting changes as those changed statements during evolution that alter privilege protection of some code. We propose an automated method that identifies protection-impacting changes within all changed statements between two versions. The proposed approach compares statically computed security protection models and repository information corresponding to different releases of a system to identify protection-impacting changes. Results of experiments present the occurrence of protection-impacting changes over 210 release pairs of WordPress, a PHP content management web application. First, we show that only 41% of the release pairs present protection-impacting changes. Second, for these affected release pairs, protection-impacting changes can be identified and represent a median of 47.00 lines of code, that is 27.41% of the total changed lines of code. Over all investigated releases in WordPress, protection-impacting changes amounted to 10.89% of changed lines of code. Conversely, an average of about 89% of changed source code have no impact on RBAC security and thus need no re-validation nor investigation. The proposed method reduces the amount of candidate causes of protection changes that developers need to investigate. This information could help developers re-validate application security, identify causes of negative security changes, and perform repairs in a more effective way.

The Internet of Things (IoT) is the latest evolution of the Internet, encompassing an enormous number of connected physical "things." The access-control oriented (ACO) architecture was recently proposed for cloud-enabled IoT, with virtual objects (VOs) and cloud services in the middle layers. A central aspect of ACO is to control communication among VOs. This paper develops operational and administrative access control models for this purpose, assuming topic-based publishsubscribe interaction among VOs. Operational models are developed using (i) access control lists for topics and capabilities for virtual objects and (ii) attribute-based access control, and it is argued that role-based access control is not suitable for this purpose. Administrative models for these two operational models are developed using (i) access control lists, (ii) role-based access control, and (iii) attribute-based access control. A use case illustrates the details of these access control models for VO communication, and their differences. An assessment of these models with respect to security and privacy preserving objectives of IoT is also provided.

As Industries and Data Center plan to implement Software Defined Networking (SDN), the main concern is the anxiety about security. The Industries and Data Centers are curious to know how a SDN product will support them that their data, supporting applications and built in infrastructure are not vulnerable to threats. The initiation of SDN, will demand new pathways for securing control plane traffic. The traditional networks usually trust switching intelligence to implement various defense mechanisms besides known attacks. Many attacks which distress traditional networks also affect SDNs, partially due to SDN architecture complexities and most prominent among them is DoS. This paper identifies the pathways of threats to SDN systems and discuss methods to ways to mitigate them.

Among the various types of Role-based access control (RBAC) policies proposed in the literature, contextual policies take into account the user's location and the time at which she requests an access. The precise characterization of the context in such policies and the definition of an access decision procedure for them are non-trivial ntasks, since they have to take into account the various facets of the temporal and spatial expressions occurring in these policies. Existing approaches for modeling contextual policies do not support all the various spatio-temporal concepts and often do not provide an access decision procedure. In this paper, we propose a model-driven approach to representing and checking RBAC contextual policies. We introduce GemRBAC+CTX, an extension of a generalized conceptual model for RBAC, which contains all the concepts required to model contextual policies. We formalize these policies as constraints, using the Object Constraint Language (OCL), on the GemRBAC+CTX model, as a way to operationalize the access decision for user's requests using model-driven technologies. We show the application of GemRBAC+CTX to model the RBAC contextual policies of an application developed by HITEC Luxembourg, a provider of situational-aware information management systems for emergency scenarios. The use of GemRBAC+CTX has allowed the engineers of HITEC to define several new types of contextual policies, with a fine-grained, precise description of contexts. The preliminary experimental results show the feasibility of applying our model-driven approach for making access decisions in real systems.

Role-based Access Control (RBAC) is a popular solution for implementing information security however there is no pervasive methodology used to produce scalable access control systems for large organizations with hundreds or thousands of employees. As a result ten engineers will likely arrive at ten different solutions to the same problem where there is no right or wrong answer but there is both an immediate and long term cost. Moreover, they would have difficulty communicating the important aspects of their design implementations to each other. This is an interesting deficiency because despite their diversity, large organizations are built upon two key concepts, roles and responsibilities, where a role like Departmental Chair is identified and assigned responsibilities. In this paper, our objective is to introduce ORGODEX, a new model and practical methodology for engineering scalable RBAC systems in large organizations where employees require access to information on a need to know basis. First, we motivate the requirement for a new RBAC dichotomy, distinguishing between roles and responsibilities. Next, we introduce our new model for describing and reasoning about RBAC systems with this new dichotomy. Finally, we produce a new iterative methodology for engineering scalable access control systems.