Context dependent revocation in delegated XACML

The XACML standard defines an XML based language for defining access control policies and a related processing model. Recent work aims to add delegation to XACML in order to express the right to administrate XACML policies within XACML itself. The delegation profile draft explains how to validate the right to issue a policy, but there are no provisions for removing a policy. This paper proposes a revocation model for delegated XACML. A novel feature of this model is that whether a revocation is valid or not, depends not only on who issued the revocation, but also on the context in which an attempt to use the revoked policy is done

Handling Confidential Data on the Untrusted Cloud: An Agent-based Approach

Cloud computing allows shared computer and storage facilities to be used by a multitude of clients. While cloud management is centralized, the information resides in the cloud and information sharing can be implemented via off-the-shelf techniques for multiuser databases. Users, however, are very diffident for not having full control over their sensitive data. Untrusted database-as-a-server techniques are neither readily extendable to the cloud environment nor easily understandable by non-technical users. To solve this problem, we present an approach where agents share reserved data in a secure manner by the use of simple grant-and-revoke permissions on shared data.Comment: 7 pages, 9 figures, Cloud Computing 201

Privacy-Preserving Facial Recognition Using Biometric-Capsules

Indiana University-Purdue University Indianapolis (IUPUI)In recent years, developers have used the proliferation of biometric sensors in smart devices, along with recent advances in deep learning, to implement an array of biometrics-based recognition systems. Though these systems demonstrate remarkable performance and have seen wide acceptance, they present unique and pressing security and privacy concerns. One proposed method which addresses these concerns is the elegant, fusion-based Biometric-Capsule (BC) scheme. The BC scheme is provably secure, privacy-preserving, cancellable and interoperable in its secure feature fusion design. In this work, we demonstrate that the BC scheme is uniquely fit to secure state-of-the-art facial verification, authentication and identification systems. We compare the performance of unsecured, underlying biometrics systems to the performance of the BC-embedded systems in order to directly demonstrate the minimal effects of the privacy-preserving BC scheme on underlying system performance. Notably, we demonstrate that, when seamlessly embedded into a state-of-the-art FaceNet and ArcFace verification systems which achieve accuracies of 97.18% and 99.75% on the benchmark LFW dataset, the BC-embedded systems are able to achieve accuracies of 95.13% and 99.13% respectively. Furthermore, we also demonstrate that the BC scheme outperforms or performs as well as several other proposed secure biometric methods

Strong and Provably Secure Database Access Control

Existing SQL access control mechanisms are extremely limited. Attackers can leak information and escalate their privileges using advanced database features such as views, triggers, and integrity constraints. This is not merely a problem of vendors lagging behind the state-of-the-art. The theoretical foundations for database security lack adequate security definitions and a realistic attacker model, both of which are needed to evaluate the security of modern databases. We address these issues and present a provably secure access control mechanism that prevents attacks that defeat popular SQL database systems.Comment: A short version of this paper has been published in the proceedings of the 1st IEEE European Symposium on Security and Privacy (EuroS&P 2016

Judicial Review of Visa Petition Revocations: A “Precedential Cascade”

The Secretary of Homeland Security has the power to revoke approved visa petitions pursuant to the grant of authority in 8 U.S.C. § 1155, part of the Immigration and Nationality Act (INA). The circuit courts disagree over whether the Secretary’s decisions under this provision are subject to judicial review. On April 7, 2020, the United States Court of Appeals for the Fourth Circuit, in Polfliet v. Cuccinelli, held that the Secretary’s authority under 8 U.S.C. § 1155 is discretionary. In doing so, the Fourth Circuit joined nine other circuit courts to find that visa petition revocation decisions are discretionary and, as such, 8 U.S.C. § 1252(a)(2)(B)(ii) precludes judicial review of the decisions. This Comment considers the impact of the 2010 Supreme Court decision, Kucana v. Holder, on the analysis of jurisdictional bars in cases like Polfliet. This Comment argues that the Fourth Circuit, in Polfliet, should have adopted the interpretive principles that the Supreme Court used in Kucana and resisted the precedential cascade

On the Certificate Revocation Problem in the Maritime Sector

Maritime shipping is currently undergoing rapid digitalization, but with increasing exposure to cyber threats, there is a need to improve the security of the ship communication technology used during operations across international waters, as well as close to local shores and in ports. To this aid, there are ongoing standardization efforts for an international maritime Public Key Infrastructure, but the inherent properties of limited connectivity and bandwidth make certificate revocation a problematic affair compared to traditional Internet systems. The main contribution of this paper is an analysis of certificate revocation techniques based on how they fulfil fundamental maritime requirements and simulated usage over time. Our results identify CRLs (with Delta CRLs) and CRLite as the two most promising candidates. Finally, we outline the pros and cons with these two different solutions.publishedVersio