A Secret Sharing Scheme for Preventing the Cheaters from Acquiring the Secret

In this paper, we propose a secret sharing scheme which prevents the cheaters from recovering the secret when the honest participants cannot, with high probability. The scheme is a (k, n) threshold scheme providing protection against less than k cheaters. It is efficient in terms of share sizes for the participants. Furthermore the total size of the individual shares per participant is less than twice the size of the secret itself. The cheaters can do successful cheating with a probability 1/t, which can be adjusted without significantly increasing the total size of the individual shares. Such a scheme can be deployed in thin client fat server systems where the server has reasonable computational power and there is a high level of mistrust among the users

Cheating Detection and Cheater Identification in CRT-based Secret Sharing Schemes

In this paper we analyze the cheating detection and cheater identification problems for the secret sharing schemes based on the Chinese remainder theorem (CRT), more exactly for Mignotte [1] and Asmuth-Bloom [2] schemes. We prove that the majority of the solutions for Shamir’s scheme [3] can be translated to these schemes and, moreover, there are some interesting specific solutions

Design of secure and trustworthy system-on-chip architectures using hardware-based root-of-trust techniques

Cyber-security is now a critical concern in a wide range of embedded computing modules, communications systems, and connected devices. These devices are used in medical electronics, automotive systems, power grid systems, robotics, and avionics. The general consensus today is that conventional approaches and software-only schemes are not sufficient to provide desired security protections and trustworthiness. Comprehensive hardware-software security solutions so far have remained elusive. One major challenge is that in current system-on-chip (SoCs) designs, processing elements (PEs) and executable codes with varying levels of trust, are all integrated on the same computing platform to share resources. This interdependency of modules creates a fertile attack ground and represents the Achilles’ heel of heterogeneous SoC architectures. The salient research question addressed in this dissertation is “can one design a secure computer system out of non-secure or untrusted computing IP components and cores?”. In response to this question, we establish a generalized, user/designer-centric set of design principles which intend to advance the construction of secure heterogeneous multi-core computing systems. We develop algorithms, models of computation, and hardware security primitives to integrate secure and non-secure processing elements into the same chip design while aiming for: (a) maintaining individual core’s security; (b) preventing data leakage and corruption; (c) promoting data and resource sharing among the cores; and (d) tolerating malicious behaviors from untrusted processing elements and software applications. The key contributions of this thesis are: 1. The introduction of a new architectural model for integrating processing elements with different security and trust levels, i.e., secure and non-secure cores with trusted and untrusted provenances; 2. A generalized process isolation design methodology for the new architecture model that covers both the software and hardware layers to (i) create hardware-assisted virtual logical zones, and (ii) perform both static and runtime security, privilege level and trust authentication checks; 3. A set of secure protocols and hardware root-of-trust (RoT) primitives to support the process isolation design and to provide the following functionalities: (i) hardware immutable identities – using physical unclonable functions, (ii) core hijacking and impersonation resistance – through a blind signature scheme, (iii) threshold-based data access control – with a robust and adaptive secure secret sharing algorithm, (iv) privacy-preserving authorization verification – by proposing a group anonymous authentication algorithm, and (v) denial of resource or denial of service attack avoidance – by developing an interconnect network routing algorithm and a memory access mechanism according to user-defined security policies. 4. An evaluation of the security of the proposed hardware primitives in the post-quantum era, and possible extensions and algorithmic modifications for their post-quantum resistance. In this dissertation, we advance the practicality of secure-by-construction methodologies in SoC architecture design. The methodology allows for the use of unsecured or untrusted processing elements in the construction of these secure architectures and tries to extend their effectiveness into the post-quantum computing era

Free riding in peer-to-peer networks

Free riding in peer-to-peer (P2P) networks poses a serious threat to their proper operation. Here, the authors present a variety of approaches developed to overcome this problem. They introduce several unique aspects of P2P networks and discuss free riding's effects on P2P services. They categorize proposed solutions and describe each category's important features and implementation issues together with some sample solutions. They also discuss open issues, including common attacks and security considerations. © 2009 IEEE

High Quality P2P Service Provisioning via Decentralized Trust Management

Trust management is essential to fostering cooperation and high quality service provisioning in several peer-to-peer (P2P) applications. Among those applications are customer-to-customer (C2C) trading sites and markets of services implemented on top of centralized infrastructures, P2P systems, or online social networks. Under these application contexts, existing work does not adequately address the heterogeneity of the problem settings in practice. This heterogeneity includes the different approaches employed by the participants to evaluate trustworthiness of their partners, the diversity in contextual factors that influence service provisioning quality, as well as the variety of possible behavioral patterns of the participants. This thesis presents the design and usage of appropriate computational trust models to enforce cooperation and ensure high quality P2P service provisioning, considering the above heterogeneity issues. In this thesis, first I will propose a graphical probabilistic framework for peers to model and evaluate trustworthiness of the others in a highly heterogeneous setting. The framework targets many important issues in trust research literature: the multi-dimensionality of trust, the reliability of different rating sources, and the personalized modeling and computation of trust in a participant based on the quality of services it provides. Next, an analysis on the effective usage of computational trust models in environments where participants exhibit various behaviors, e.g., honest, rational, and malicious, will be presented. I provide theoretical results showing the conditions under which cooperation emerges when using trust learning models with a given detecting accuracy and how cooperation can still be sustained while reducing the cost and accuracy of those models. As another contribution, I also design and implement a general prototyping and simulation framework for reputation-based trust systems. The developed simulator can be used for many purposes, such as to discover new trust-related phenomena or to evaluate performance of a trust learning algorithm in complex settings. Two potential applications of computational trust models are then discussed: (1) the selection and ranking of (Web) services based on quality ratings from reputable users, and (2) the use of a trust model to choose reliable delegates in a key recovery scenario in a distributed online social network. Finally, I will identify a number of various issues in building next-generation, open reputation-based trust management systems as well as propose several future research directions starting from the work in this thesis

Preventing Insider Theft: Lessons from the Casino and Pharmaceutical Industries

Through structured interviews and a literature review, we assess which approaches to protection against insider thefts in the casino and pharmaceutical industries could be usefully applied to strengthen protections against insider theft in the nuclear industry, where insider thefts could have very high consequences. Among other measures, we suggest consideration of constant video surveillance of all vaults and insider-material interactions; frequent and rigorous material accounting; requiring everyone who touches material to sign for it; implementing an expanded two-person rule; rewarding attention to security; and establishing incident databases and experience sharing. While many of these measures are in place for some operations with weapons-usable material in some countries, they should be considered for more universal application

Secure Routing and Medium Access Protocols inWireless Multi-hop Networks

While the rapid proliferation of mobile devices along with the tremendous growth of various applications using wireless multi-hop networks have significantly facilitate our human life, securing and ensuring high quality services of these networks are still a primary concern. In particular, anomalous protocol operation in wireless multi-hop networks has recently received considerable attention in the research community. These relevant security issues are fundamentally different from those of wireline networks due to the special characteristics of wireless multi-hop networks, such as the limited energy resources and the lack of centralized control. These issues are extremely hard to cope with due to the absence of trust relationships between the nodes. To enhance security in wireless multi-hop networks, this dissertation addresses both MAC and routing layers misbehaviors issues, with main focuses on thwarting black hole attack in proactive routing protocols like OLSR, and greedy behavior in IEEE 802.11 MAC protocol. Our contributions are briefly summarized as follows. As for black hole attack, we analyze two types of attack scenarios: one is launched at routing layer, and the other is cross layer. We then provide comprehensive analysis on the consequences of this attack and propose effective countermeasures. As for MAC layer misbehavior, we particularly study the adaptive greedy behavior in the context of Wireless Mesh Networks (WMNs) and propose FLSAC (Fuzzy Logic based scheme to Struggle against Adaptive Cheaters) to cope with it. A new characterization of the greedy behavior in Mobile Ad Hoc Networks (MANETs) is also introduced. Finally, we design a new backoff scheme to quickly detect the greedy nodes that do not comply with IEEE 802.11 MAC protocol, together with a reaction scheme that encourages the greedy nodes to become honest rather than punishing them

Secure Routing and Medium Access Protocols inWireless Multi-hop Networks

While the rapid proliferation of mobile devices along with the tremendous growth of various applications using wireless multi-hop networks have significantly facilitate our human life, securing and ensuring high quality services of these networks are still a primary concern. In particular, anomalous protocol operation in wireless multi-hop networks has recently received considerable attention in the research community. These relevant security issues are fundamentally different from those of wireline networks due to the special characteristics of wireless multi-hop networks, such as the limited energy resources and the lack of centralized control. These issues are extremely hard to cope with due to the absence of trust relationships between the nodes. To enhance security in wireless multi-hop networks, this dissertation addresses both MAC and routing layers misbehaviors issues, with main focuses on thwarting black hole attack in proactive routing protocols like OLSR, and greedy behavior in IEEE 802.11 MAC protocol. Our contributions are briefly summarized as follows. As for black hole attack, we analyze two types of attack scenarios: one is launched at routing layer, and the other is cross layer. We then provide comprehensive analysis on the consequences of this attack and propose effective countermeasures. As for MAC layer misbehavior, we particularly study the adaptive greedy behavior in the context of Wireless Mesh Networks (WMNs) and propose FLSAC (Fuzzy Logic based scheme to Struggle against Adaptive Cheaters) to cope with it. A new characterization of the greedy behavior in Mobile Ad Hoc Networks (MANETs) is also introduced. Finally, we design a new backoff scheme to quickly detect the greedy nodes that do not comply with IEEE 802.11 MAC protocol, together with a reaction scheme that encourages the greedy nodes to become honest rather than punishing them

How Community Institutions Create Economic Advantage: Jewish Diamond Merchants in New York

This paper argues that Jewish merchants have historically dominated the diamond industry because of their ability to reliably implement diamond credit sales. Success in the industry requires enforcing executory agreements that are beyond the reach of public courts, and Jewish diamond merchants enforce such contracts with a reputation mechanism supported by a distinctive set of industry, family, and community institutions. An industry arbitration system publicizes promises that are not kept. Intergenerational legacies induce merchants to deal honestly through their very last transaction, so that their children may inherit valuable livelihoods. And ultra-Orthodox Jews, for whom participation in their communities is paramount, provide important value-added services to the industry without posing the threat of theft and flight