Biblio

To instill greater confidence in computations outsourced to the cloud, clients should be able to verify the correctness of the results returned. To this end, we introduce Pinocchio, a built system for efficiently verifying general computations while relying only on cryptographic assumptions. With Pinocchio, the client creates a public evaluation key to describe her computation; this setup is proportional to evaluating the computation once. The worker then evaluates the computation on a particular input and uses the evaluation key to produce a proof of correctness. The proof is only 288 bytes, regardless of the computation performed or the size of the inputs and outputs. Anyone can use a public verification key to check the proof. Crucially, our evaluation on seven applications demonstrates that Pinocchio is efficient in practice too. Pinocchio's verification time is typically 10ms: 5-7 orders of magnitude less than previous work; indeed Pinocchio is the first general-purpose system to demonstrate verification cheaper than native execution (for some apps). Pinocchio also reduces the worker's proof effort by an additional 19-60x. As an additional feature, Pinocchio generalizes to zero-knowledge proofs at a negligible cost over the base protocol. Finally, to aid development, Pinocchio provides an end-to-end toolchain that compiles a subset of C into programs that implement the verifiable computation protocol.

Memory corruption bugs in software written in low-level languages like C or C++ are one of the oldest problems in computer security. The lack of safety in these languages allows attackers to alter the program's behavior or take full control over it by hijacking its control flow. This problem has existed for more than 30 years and a vast number of potential solutions have been proposed, yet memory corruption attacks continue to pose a serious threat. Real world exploits show that all currently deployed protections can be defeated. This paper sheds light on the primary reasons for this by describing attacks that succeed on today's systems. We systematize the current knowledge about various protection techniques by setting up a general model for memory corruption attacks. Using this model we show what policies can stop which attacks. The model identifies weaknesses of currently deployed techniques, as well as other proposed protections enforcing stricter policies. We analyze the reasons why protection mechanisms implementing stricter polices are not deployed. To achieve wide adoption, protection mechanisms must support a multitude of features and must satisfy a host of requirements. Especially important is performance, as experience shows that only solutions whose overhead is in reasonable bounds get deployed. A comparison of different enforceable policies helps designers of new protection mechanisms in finding the balance between effectiveness (security) and efficiency. We identify some open research problems, and provide suggestions on improving the adoption of newer techniques.

Privacy has become a critical topic in the engineering of electric systems. This work proposes an approach for smart-grid-specific privacy requirements engineering by extending previous general privacy requirements engineering frameworks. The proposed extension goes one step further by focusing on privacy in the smart grid. An alignment of smart grid privacy requirements, dependability issues and privacy requirements engineering methods is presented. Starting from this alignment a Threat Tree Analysis is performed to obtain a first set of generic, high level privacy requirements. This set is formulated mostly on the data instead of the information level and provides the basis for further project-specific refinement.

In previous multi-authority key-policy attribute-based Encryption (KP-ABE) schemes, either a super power central authority (CA) exists, or multiple attribute authorities (AAs) must collaborate in initializing the system. In addition, those schemes are proved security in the selective model. In this paper, we propose a new fully secure decentralized KP-ABE scheme, where no CA exists and there is no cooperation between any AAs. To become an AA, a participant needs to create and publish its public parameters. All the user's private keys will be linked with his unique global identifier (GID). The proposed scheme supports any monotonic access structure which can be expressed by a linear secret sharing scheme (LSSS). We prove the full security of our scheme in the standard model. Our scheme is also secure against at most F-1 AAs corruption, where F is the number of AAs in the system. The efficiency of our scheme is almost as well as that of the underlying fully secure single-authority KP-ABE system.

Cyber-has often been considered as a coordination and control, as opposed to collaborative influence, media. This conceptual-design paper, uniquely, builds upon a number of entangled, cross disciplinary research strands – integrating engineering and conflict studies – and a detailed literature review to propose a new paradigm of assurance and deterrence models. We consider an ontology for Cyber-sûréte, which combines both the social trusts necessary for [knowledge &, information] assurance such as collaboration by social influence (CSI) and the technological controls and rules for secure information management referred as coordination by rule and control (CRC). We posit Cyber-sûréte as enabling both a 'safe-to-fail' ecology (in which learning, testing and adaptation can take place) within a fail-safe supervisory control and data acquisition (SCADA type) system, e.g. in a nuclear power plant. Building upon traditional state-based threat analysis, we consider Warning Time and the Threat equation with relation to policies for managing Cyber-Deterrence. We examine how the goods of Cyber-might be galvanised so as to encourage virtuous behaviour and deter and / or dissuade ne'er-do-wells through multiple transparencies. We consider how the Deterrence-escalator may be managed by identifying both weak influence and strong control signals so as to create a more benign and responsive cyber-ecology, in which strengths can be exploited and weaknesses identified. Finally, we consider declaratory / mutual transparencies as opposed to legalistic / controlled transparency.

Access policies are hard to express in existing programming languages. However, their accurate expression is a prerequisite for many of today's applications. We propose a new language that uses classes, first-class relationships, and first-class states to express access policies in a more declarative and fine-grained way than existing solutions allow.

This paper describes a Cyber Threat, Vulnerability and Defense Modeling and Simulation tool kit used for evaluation of systems and networks to improve cyber resiliency. This capability is used to help increase the resiliency of networks at various stages of their lifecycle, from initial design and architecture through the operation of deployed systems and networks. Resiliency of computer systems and networks to cyber threats is facilitated by the modeling of agile and resilient defenses versus threats and running multiple simulations evaluated against resiliency metrics. This helps network designers, cyber analysts and Security Operations Center personnel to perform trades using what-if scenarios to select resiliency capabilities and optimally design and configure cyber resiliency capabilities for their systems and networks.

Researchers interested in security often wish to introduce new primitives into a language. Extensible languages hold promise in such scenarios, but only if the extension mechanism is sufficiently safe and expressive. This paper describes several modifications to an extensible language motivated by end-to-end security concerns.

Cyber-physical systems are particularly difficult to model and simulate because their components mix many different system modalities. In this paper we address the main technical challenges on system simulation taking into account by new characters of CPS, and provide a comprehensive view of the simulation modeling methods for integration of continuous-discrete model. Regards to UML and Simulink, two most widely accepted modeling methods in industrial designs, we study on three methods to perform the cooperation of these two kinds of heterogeneous models for co-simulation. The solution of an implementation of co-simulation method for CPS was designed under three levels architecture.

This study looks at the question of how to reduce/eliminate employee Internet Abuse. Companies have used acceptable use policies (AUP) and technology in an attempt to mitigate employees' personal use of company resources. Research shows that AUPs do not do a good job at this but that technology does. Research also shows that while technology can be used to greatly restrict personal use of the internet in the workplace, employee satisfaction with the workplace suffers when this is done. In this research experiment we used technology not to restrict employee use of company resources for personal use, but to make the employees more aware of the current Acceptable Use Policy, and measured the decrease in employee internet abuse. The results show that this method can result in a drop from 27 to 21 percent personal use of the company networks.

Despite the benefits offered by smart grids, energy producers, distributors and consumers are increasingly concerned about possible security and privacy threats. These threats typically manifest themselves at runtime as new usage scenarios arise and vulnerabilities are discovered. Adaptive security and privacy promise to address these threats by increasing awareness and automating prevention, detection and recovery from security and privacy requirements' failures at runtime by re-configuring system controls and perhaps even changing requirements. This paper discusses the need for adaptive security and privacy in smart grids by presenting some motivating scenarios. We then outline some research issues that arise in engineering adaptive security. We particularly scrutinize published reports by NIST on smart grid security and privacy as the basis for our discussions.

Very often in the software development life cycle, security is applied too late or important security aspects are overlooked. Although the use of security patterns is gaining popularity, the current state of security requirements patterns is such that there is not much in terms of a defining structure. To address this issue, we are working towards defining the important characteristics as well as the boundaries for security requirements patterns in order to make them more effective. By examining an existing general pattern format that describes how security patterns should be structured and comparing it to existing security requirements patterns, we are deriving characterizations and boundaries for security requirements patterns. From these attributes, we propose a defining format. We hope that these can reduce user effort in elicitation and specification of security requirements patterns.

An examination of the ways cyberspace is changing both the theory and the practice of international relations. Cyberspace is widely acknowledged as a fundamental fact of daily life in today's world. Until recently, its political impact was thought to be a matter of low politics—background conditions and routine processes and decisions. Now, however, experts have begun to recognize its effect on high politics—national security, core institutions, and critical decision processes. In this book, Nazli Choucri investigates the implications of this new cyberpolitical reality for international relations theory, policy, and practice. The ubiquity, fluidity, and anonymity of cyberspace have already challenged such concepts as leverage and influence, national security and diplomacy, and borders and boundaries in the traditionally state-centric arena of international relations. Choucri grapples with fundamental questions of how we can take explicit account of cyberspace in the analysis of world politics and how we can integrate the traditional international system with its cyber venues. After establishing the theoretical and empirical terrain, Choucri examines modes of cyber conflict and cyber cooperation in international relations; the potential for the gradual convergence of cyberspace and sustainability, in both substantive and policy terms; and the emergent synergy of cyberspace and international efforts toward sustainable development. Choucri's discussion is theoretically driven and empirically grounded, drawing on recent data and analyzing the dynamics of cyberpolitics at individual, state, international, and global levels.

Software patterns are created with the goal of capturing expert
knowledge so it can be efficiently and effectively shared with the
software development community. However, patterns in practice
may or may not achieve these goals. Empirical studies of the use
of software patterns can help in providing deeper insight into
whether these goals have been met. The objective of this paper is
to aid researchers in designing empirical studies of software
patterns by summarizing the study designs of software patterns
available in the literature. The important components of these
study designs include the evaluation criteria and how the patterns
are presented to study participants. We select and analyze 19
distinct empirical studies and identify 17 independent variables in
three different categories (participants demographics; pattern
presentation; problem presentation). We also extract 10 evaluation
criteria with 23 associated observable measures. Additionally, by
synthesizing the reported observations, we identify challenges
faced during study execution. Provision of multiple domainspecific
examples of pattern application and tool support to assist
in pattern selection are helpful for the study participants in
understanding and completing the study task. Capturing data
regarding the cognitive processes of participants can provide
insights into the findings of the study.