In contrast to today's IP-based host-oriented Internet architecture, Information-Centric Networking (ICN) emphasizes content by making it directly addressable and routable. Named Data Networking (NDN) architecture is an instance of ICN that is being developed as a candidate next-generation Internet architecture. By opportunistically caching content within the network, NDN appears to be well-suited for large-scale content distribution and for meeting the needs of increasingly mobile and bandwidth-hungry applications that dominate today's Internet. One key feature of NDN is the requirement for each content object to be digitally signed by its producer. Thus, NDN should be, in principle, immune to distributing fake (aka "poisoned") content. However, in practice, this poses two challenges for detecting fake content in NDN routers: (1) overhead due to signature verification and certificate chain traversal, and (2) lack of trust context, i.e., determining which public keys are trusted to verify which content. Because of these issues, NDN does not force routers to verify content signatures, which makes the architecture susceptible to content poisoning attacks. This paper explores root causes of, and some cures for, content poisoning attacks in NDN. In the process, it becomes apparent that meaningful mitigation of content poisoning is contingent upon a network-layer trust management architecture, elements of which we construct, while carefully justifying specific design choices. This work represents the initial effort towards comprehensive trust management for NDN.
Policymaker @cite_26 is a tool that provides privacy and authenticity for network services. It offers a flexible and unified language for expressing policies and relationships. It also includes a local (per site or network) engine for carrying all trust operations, such as granting access to services.
@cite_26
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In this paper, we present an approach for analyzing the integrity protection in the SELinux example policy. The SELinux example policy is intended as an example from which administrators customize to create a policy for their site's security goals, but the complexity of the model and size of the policy make this quite complex. Our aim is to provide an access control model to express site security goals and resolve them against the SELinux policy. Ultimately, we aim to define a minimal trusted computing base (TCB) that satisfies Clark-Wilson integrity, by first testing for the more restrictive Biba integrity policy and resolving conflicts using Clark-Wilson semantics. Our policy analysis tool, Gokyo, implements the following approach: (1) it represents the SELinux example policy and our integrity goals; (2) it identifies conflicts between them; (3) it estimates the resolutions to these conflicts; and (4) provides information for deciding upon a resolution. Using Gokyo, we derive a proposal for a minimal TCB for SELinux includes 30 subject types, and we identify the work remaining to ensure that TCB is integrity-protected. Our analysis is performed on the SELinux example policy for Linux 2.4.19. Today organizations do not have good ways of linking their written privacy policies with the implementation of those policies. To assist organizations in addressing this issue, our human-centered research has focused on understanding organizational privacy management needs, and, based on those needs, creating a usable and effective policy workbench called SPARCLE. SPARCLE will enable organizational users to enter policies in natural language, parse the policies to identify policy elements and then generate a machine readable (XML) version of the policy. In the future, SPARCLE will then enable mapping of policies to the organization's configuration and provide audit and compliance tools to ensure that the policy implementation operates as intended. In this paper, we present the strategies employed in the design and implementation of the natural language parsing capabilities that are part of the functional version of the SPARCLE authoring utility. We have created a set of grammars which execute on a shallow parser that are designed to identify the rule elements in privacy policy rules. We present empirical usability evaluation data from target organizational users of the SPARCLE system and highlight the parsing accuracy of the system with the organizations' privacy policies. The successful implementation of the parsing capabilities is an important step towards our goal of providing a usable and effective method for organizations to link the natural language version of privacy policies to their implementation, and subsequent verification through compliance auditing of the enforcement logs. Understanding the privacy implication of adopting a certain privacy setting is a complex task for the users of social network systems. Users need tool support to articulate potential access scenarios and perform policy analysis. Such a need is particularly acute for Facebook-style Social Network Systems (FSNSs), in which semantically rich topology-based policies are used for access control. In this work, we develop a prototypical tool for Reflective Policy Assessment (RPA) --- a process in which a user examines her profile from the viewpoint of another user in her extended neighbourhood in the social graph. We verify the utility and usability of our tool in a within-subject user study. The RT Role-based Trust-management framework provides policy language, semantics, deduction engine, and pragmatic features such as application domain specification documents that help distributed users maintain consistent use of policy terms. This paper provides a general overview of the framework, combining some aspects described in previous publications with recent improvements and explanation of motivating applications.