997 research outputs found

    User acceptance of intelligent avionics: A study of automatic-aided target recognition

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    User acceptance of new support systems typically was evaluated after the systems were specified, designed, and built. The current study attempts to assess user acceptance of an Automatic-Aided Target Recognition (ATR) system using an emulation of such a proposed system. The detection accuracy and false alarm level of the ATR system were varied systematically, and subjects rated the tactical value of systems exhibiting different performance levels. Both detection accuracy and false alarm level affected the subjects' ratings. The data from two experiments suggest a cut-off point in ATR performance below which the subjects saw little tactical value in the system. An ATR system seems to have obvious tactical value only if it functions at a correct detection rate of 0.7 or better with a false alarm level of 0.167 false alarms per square degree or fewer

    DATA INSECURITY LAW

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    By broad consensus, data security laws have failed to stem a rising tide of data breaches. Lawmakers and commentators blame these failures on some combination of underenforcement and the laws failure to recognize the full range of data breach harms. Proposed solutions would augment or expand existing data security laws. These proposed solutions share a fatal flaw: they are rooted in traditional theories of deterrence by punishment. Data security laws come in three forms: duties to protect data, duties to notify consumers after a breach, and post-breach remedies. Almost every data security law is enforced through sanctions, most of which are applied after a company discovers a data breach. In theory, companies increase their data security efforts to avoid sanctions. While appropriate for companies that purchase software, this approach is ineffective when applied to companies that build and provide software as an online service. In the cloud context, improving cybersecurity practices increases expected sanctions. And the cloud context matters. Online data security implicates almost all personal data; online services hold the lion’s share of personal data and offline firms rely heavily on cloud software to operate their businesses. This Article calls for a new approach to data security regulation, founded on a systemic view of data security practice. By focusing on system-level incentives instead of individual outcomes, lawmakers can bring data security law back into harmony with policy goals

    Smart Learning to Find Dumb Contracts

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    We introduce Deep Learning Vulnerability Analyzer (DLVA), a vulnerability detection tool for Ethereum smart contracts based on powerful deep learning techniques for sequential data adapted for bytecode. We train DLVA to judge bytecode even though the supervising oracle, Slither, can only judge source code. DLVA's training algorithm is general: we "extend" a source code analysis to bytecode without any manual feature engineering, predefined patterns, or expert rules. DLVA's training algorithm is also robust: it overcame a 1.25% error rate mislabeled contracts, and the student surpassing the teacher; found vulnerable contracts that Slither mislabeled. In addition to extending a source code analyzer to bytecode, DLVA is much faster than conventional tools for smart contract vulnerability detection based on formal methods: DLVA checks contracts for 29 vulnerabilities in 0.2 seconds, a speedup of 10-500x+ compared to traditional tools. DLVA has three key components. Smart Contract to Vector (SC2V) uses neural networks to map arbitrary smart contract bytecode to an high-dimensional floating-point vector. Sibling Detector (SD) classifies contracts when a target contract's vector is Euclidian-close to a labeled contract's vector in a training set; although only able to judge 55.7% of the contracts in our test set, it has an average accuracy of 97.4% with a false positive rate of only 0.1%. Lastly, Core Classifier (CC) uses neural networks to infer vulnerable contracts regardless of vector distance. DLVA has an overall accuracy of 96.6% with an associated false positive rate of only 3.7%

    PTE: Axiomatic Semantics based Compiler Testing

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    The correctness of a compiler affects the correctness of every program written in the language, and thus must be thoroughly evaluated. Existing automatic compiler testing methods however either rely on weak oracles (e.g., a program behaves the same if only dead code is modified), or require substantial initial effort (e.g., having a complete operational language semantics). While the former prevents a comprehensive correctness evaluation, the latter makes those methods irrelevant in practice. In this work, we propose an axiomatic semantics based approach for testing compilers, called PTE. The idea is to incrementally develop a set of ``axioms'' capturing anecdotes of the language semantics in the form of \emph{(\textbf{p}recondition, \textbf{t}ransformation, \textbf{e}xpectation) triples, which allows us to test the compiler automatically.} Such axioms are written in the same language whose compiler is under test, and can be developed either based on the language specification, or by generalizing the bug reports. PTE has been applied to a newly developed compiler (i.e., Cangjie) and a mature compiler (i.e., Java), and successfully identified 42 implementation bugs and 9 potential language design issues

    Network Intrusion Detection and Mitigation Against Denial of Service Attack

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    The growing use of Internet service in the past few years have facilitated an increase in the denial of service (DoS) attacks. Despite the best preventative measures, DoS attacks have been successfully carried out against high-prole organizations and enterprises, including those that took down Chase, BOA, PNC and other major US banks in September 2009, which reveal the vulnerability of even well equipped networks. These widespread attacks have resulted in significant loss of service, money, and reputation for organizations, calling for a practical and ecient solution to DoS attack detection and mitigation. DoS attack detection and mitigation strengthens the robustness and security of network or computer system, by monitoring system activities for suspicious behaviors or policy violations, providing forensic information about the attack, and taking defensive measures to reduce the impact on the system. In general, attacks can be detected by (1) matching observed network trac with patterns of known attacks; (2) looking for deviation of trac behavior from the established prole; and (3) training a classier from labeled dataset of attacks to classify incoming trac. Once an attack is identied, the suspicious trac can be blocked or rate limited. In this presentation, we present a taxonomy of DoS attack detection and mitigation techniques, followed by a description of four representative systems (Snort, PHAD, MADAM, and MULTOPS). We conclude with a discussion of their pros/cons as well as challenges for future work

    Automatic program analysis in a Prolog Intelligent Teaching System

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    Anomaly-based Correlation of IDS Alarms

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    An Intrusion Detection System (IDS) is one of the major techniques for securing information systems and keeping pace with current and potential threats and vulnerabilities in computing systems. It is an indisputable fact that the art of detecting intrusions is still far from perfect, and IDSs tend to generate a large number of false IDS alarms. Hence human has to inevitably validate those alarms before any action can be taken. As IT infrastructure become larger and more complicated, the number of alarms that need to be reviewed can escalate rapidly, making this task very difficult to manage. The need for an automated correlation and reduction system is therefore very much evident. In addition, alarm correlation is valuable in providing the operators with a more condensed view of potential security issues within the network infrastructure. The thesis embraces a comprehensive evaluation of the problem of false alarms and a proposal for an automated alarm correlation system. A critical analysis of existing alarm correlation systems is presented along with a description of the need for an enhanced correlation system. The study concludes that whilst a large number of works had been carried out in improving correlation techniques, none of them were perfect. They either required an extensive level of domain knowledge from the human experts to effectively run the system or were unable to provide high level information of the false alerts for future tuning. The overall objective of the research has therefore been to establish an alarm correlation framework and system which enables the administrator to effectively group alerts from the same attack instance and subsequently reduce the volume of false alarms without the need of domain knowledge. The achievement of this aim has comprised the proposal of an attribute-based approach, which is used as a foundation to systematically develop an unsupervised-based two-stage correlation technique. From this formation, a novel SOM K-Means Alarm Reduction Tool (SMART) architecture has been modelled as the framework from which time and attribute-based aggregation technique is offered. The thesis describes the design and features of the proposed architecture, focusing upon the key components forming the underlying architecture, the alert attributes and the way they are processed and applied to correlate alerts. The architecture is strengthened by the development of a statistical tool, which offers a mean to perform results or alert analysis and comparison. The main concepts of the novel architecture are validated through the implementation of a prototype system. A series of experiments were conducted to assess the effectiveness of SMART in reducing false alarms. This aimed to prove the viability of implementing the system in a practical environment and that the study has provided appropriate contribution to knowledge in this field

    Artificial intelligence based condition monitoring of rail infrastructure

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