Showing papers on "Vulnerability (computing) published in 1994"

Application of artificial neural networks in power system security and vulnerability assessment

Abstract: In a companion paper by A.A. Fouad et al. the concept of system vulnerability is introduced as a new framework for power system dynamic security assessment. Using the transient energy function (TEF) method of transient stability analysis, the energy margin /spl Delta/V is used as an indicator of the level of security, and its sensitivity to a changing system parameter p (/spl delta//spl Delta/V//spl delta/p) as an indicator of its trend with changing system conditions. These two indicators are combined to determine the degree of system vulnerability to contingent disturbances in a stability-limited power system. Thresholds for acceptable levels of the security indicator and its trend are related to the stability limits of a critical system parameter (plant generation limits). Operating practices and policies are used to determine these thresholds. In this paper the artificial neural networks (ANNs) technique is applied to the concept of system vulnerability within the recently developed framework, for fast pattern recognition and classification of system dynamic security status. A suitable topology for the neural network is developed, and the appropriate training method and input and output signals are selected. The procedure developed is successfully applied to the IEEE 50-generator test system. Data previously obtained by heuristic techniques are used for training the ANN. >

Building information systems for mobile environments

Abstract: It is expected that in the near future, tens of millions of users will have access to distributed information systems through wireless connections. The technical characteristics of the wireless medium and the resulting mobility of both data resources and data consumers raise new challenging questions regarding the development of information systems appropriate for mobile environments. In this paper, we report on the development of such a system. First, we describe the general architecture of the information system and the main considerations of our design. Then, based on these considerations, we present our system support for maintaining the consistency of replicated data and for providing transaction schemas that account for the frequent but predictable disconnections, the mobility, and the vulnerability of the wireless environment.

Q-V curve interpretations of energy measures for voltage security

Abstract: Energy methods have shown promise as measures for quantifying the vulnerability of power systems to problems of voltage instability and collapse. However, to make such measures more useful as a security assessment tool in an operational environment. It is important to provide physical interpretations of the quantitative measure. This paper demonstrates that for certain basic load models, the energy based security measure is equal to the area enclosed by a familiar Q-V curve, with a change of scale on the voltage axis. This interpretation has the added benefit of providing easily computed approximations to the maximum real and reactive power loadability both at individual buses and for the system as a whole. Results are demonstrated in detail on the IEEE 118 bus system, with additional tests on a 415 bus sample system. >

Method and apparatus for protecting software executing on a demonstration computer

Abstract: Demonstration (demo) application software and various utility software programs are configured as a novel "protected demonstration environment" having layered security mechanisms for protecting the integrity of software executing on a computer. The security mechanisms include an underlying activity timer for ensuring that the demo program is periodically running in the absence of user input activity. When the demo program is not running, additional security mechanisms, such as message filters and icon disablers, are provided to reduce the vulnerability of the system. These security mechanisms cooperate to provide users access to certain innocuous features of the software through a graphical desktop interface on a computer screen, while preventing access to potentially destructive features.

Envisioning power system data: vulnerability and severity representations for static security assessment

Abstract: This paper deals with graphical representations for power system static security assessment. Previous work has developed a graphical representation for a single power system state. This work develops graphical representations for a global display of power system security, using basic visualization principles previously established, that efficiently and effectively communicates the influence of the contingency set on the power system. Such representations are increasingly necessary because of the growing speed with which hardware can generate data. The problem is no longer computing the answers, the problem now is understanding them. Graphical visualization is a key part of the solution. In this paper, visualizations for security assessment are developed based on standard performance indices. These convey the following information: (1) how the loss of one element affects the rest of the system, i.e. the severity of the loss of each element, and (2) how each element of the power system is affected by the contingency set, i.e. the vulnerability of that element. These two different aspects of security require two different representations, and some simple user interactions to move between them. A key benefit of visualization is the display of severity or vulnerability results from the entire contingency set on one page in a geographic context. >

Apparatus for securing the integrity of a functioning system

Abstract: Apparatus is provided for securing the integrity of a functioning system. The apparatus comprises a primary device for performing a function having a first vulnerability and a secondary device having a second vulnerability which is identical to the first vulnerability of the primary device. The secondary device is adapted to secure the function performed by the primary device in response to activity breaching the second vulnerability.

Methods For Ship Military Effectiveness Analysis

Abstract: Ship design and technology selections can be based on complete systems analysis results if one is willing to perform military effectiveness analysis. In the past, these selections have been based on ship size and performance analysis alone, but with improved techniques, comprehensive system analysis on ships can be performed. System analysis is most illuminating because it factors in threat, ship size, cost, weaponry, signatures, vulnerability, decoys/jamming and availability. The purpose of this paper is to explore military effectiveness methodology, develop key relations and show some useful results. The techniques proposed can be used in elaborate computer models for in-depth studies or in simplified linear relations to gain understanding of the interrelation of the variables and result trends.

A review of research and methods for producing high-consequence software

Abstract: The development of software for use in high-consequence systems mandates rigorous (formal) processes, methods, and techniques to improve the safety characteristics of those systems. This paper provides a brief overview of current research and practices in high-consequence software, including applied design methods. Some of the practices that are discussed include: fault tree analysis, failure mode effects analysis, petri nets, both hardware and software interlocks, n-version programming, Independent Vulnerability Analyses, and watchdogs. Techniques that offer improvement in the dependability of software in high-consequence systems applications are identified and discussed. Limitations of these techniques are also explored. Research in formal methods, the cleanroom process, and reliability models are reviewed. In addition, current work by several leading researchers as well as approaches being used by leading practitioners are examined.

An automated computer misuse detection system for UNICOS

Abstract: An effective method for detecting computer misuse is the automatic monitoring and analysis of on-line user activity. This activity is reflected in the system audit record, in the system vulnerability posture, and in other evidence found through active testing of the system. During the last several years we have implemented an automatic misuse detection system at Los Alamos. This is the Network Anomaly Detection and Intrusion Reporter (NADIR). We are currently expanding NADIR to include processing of the Cray UNICOS operating system. This new component is called the UNICOS Realtime NADIR, or UNICORN. UNICORN summarizes user activity and system configuration in statistical profiles. It compares these profiles to expert rules that define security policy and improper or suspicious behavior. It reports suspicious behavior to security auditors and provides tools to aid in follow-up investigations. The first phase of UNICORN development is nearing completion, and will be operational in late 1994.

Security in a Dependability Perspective

Abstract: Historically security has developed as a discipline, separate from the original dependability framework, which included reliability, availability and safety attributes. Therefore, the integration of security in this framework has not yet been fully accomplished. This paper presents a novel approach to security, intended to facilitate and improve this integration. This is achieved by taking a dependability viewpoint on traditional security and interpreting it in behavioural and preventive terms. A modified security concept, comprising only preventive characteristics is defined where confidentiality is suggested to be a behavioural dependability attribute. The outcome of this interpretation influences the integration of the other three dependability attributes. The overall objective of this approach is to arrive at a more general and clear-cut dependability framework that would describe how (un)dependable a system is, irrespective of the reason for the (un)dependability. For example, it should be possible to treat a system failure due to an intentional intrusion of due to a hardware fault using the same methods and in parallel. Finally, the problem of interpreting concepts and terminology for security impairments in dependability terms is addressed, based on a few examples from real security breaches. It is realized that this is an area where future work is necessary.

Expert-systems for sea mine warfare

Abstract: In this paper, the probabilistic inference network (PIN) in a decision support systems environment is used to deal with several uncertain questions. The PIN method is supported by the certainty factors. Calculations involving quantitative probabilities for answering concerned questions enable mine countermeasure (MCM) experts to offer suggestions to a commander for reducing the ship's vulnerability at sea during wartime. For sea mine warfare scenarios, based on an analysis, we have a degree of confidence of 0.6568 to suggest the commander to deploy MCM forces.

National Information Infrastructure (NII) reliability and survivability initiatives

Abstract: A joint industry-government telecommunications planning mechanism, which is already in place, is being used to address reliability and survivability issues for the National Information Infrastructure (NII). The Information Infrastructure Task Force (IITF) established four groups to address applications and technology, information policy, telecommunications policy, and security issues for the NII. The Reliability and Vulnerability Working Group (RVWG) was established under the Telecommunications Policy Committee. Its purpose is to identify policies and procedures needed to ensure that the NII telecommunications services and information systems will provide high quality service for normal operations and the maximum availability of services to meet public, private, and commercial needs, as well as national security and emergency preparedness (NS/EP) requirements. These NS/EP requirements include communications capabilities needed by Federal, State, and local emergency officials to prepare for, respond to, and recover from any national emergency, such as hostile attacks, electronic intrusions, or natural and technological disasters. >

Security Audit Center--a suggested model for effective audit strategies in health care informatics.

Abstract: As dependence upon interorganizational and international health care informatics becomes absolute, and with increased vulnerability of information networks and applications and the cunning sophistication of computer criminals, it becomes imperative to implement tight information systems security to ward off any possible threat to these vital life-dependent information systems. In a rapidly decentralizing environment, the author proposes centralized security control, implemented in a Security Audit Center under the direct supervision of an Information Systems Security Manager who is a high-ranking organization staff member. Of the various components of the Security Audit Center, the most significant is the security audit expert systems which analyze audit data files according to security rules and present a precise status of systems security and realtime suspicion alert of the various breaches and intrusions.

Security for individual computing environments

Abstract: This issue of the SIGICE Bulletin has a focus of those aspects of security called secrecy and availability. Many of us, like the authors of one of the articles, asks the question, "Is security for PC's and workstations an oxymoron?" Individual Computing Environments (ICE), i.e., PC's, workstations, etc. often appear to most of us as being extremely vulnerable to a variety of secrecy and availability breaches with little one can do about the problems. What you will learn from the articles presented in this volume is that despite the vulnerability, these machines can be secured to the point of reducing the risk to a level one is willing to tolerate. The solutions suggested go beyond the commonly used virus detection and elimination software. I urge all who own or use individual computing environments on which data and programs reside to read this series of articles.

Failure environment analysis tool applications

Abstract: Understanding risks and avoiding failure are daily concerns for the women and men of NASA. Although NASA's mission propels us to push the limits of technology, and though the risks are considerable, the NASA community has instilled within it, the determination to preserve the integrity of the systems upon which our mission and, our employees lives and well-being depend. One of the ways this is being done is by expanding and improving the tools used to perform risk assessment. The Failure Environment Analysis Tool (FEAT) was developed to help engineers and analysts more thoroughly and reliably conduct risk assessment and failure analysis. FEAT accomplishes this by providing answers to questions regarding what might have caused a particular failure; or, conversely, what effect the occurrence of a failure might have on an entire system. Additionally, FEAT can determine what common causes could have resulted in other combinations of failures. FEAT will even help determine the vulnerability of a system to failures, in light of reduced capability. FEAT also is useful in training personnel who must develop an understanding of particular systems. FEAT facilitates training on system behavior, by providing an automated environment in which to conduct 'what-if' evaluation. These types of analyses make FEAT a valuable tool for engineers and operations personnel in the design, analysis, and operation of NASA space systems.