17086760
Cost profile of a highly assured, secure operating system
The Logical Coprocessing Kernel (LOCK) began as a research project to stretch the state of the art in secure computing by trying to meet or even exceed the “A1” requirements of the Trusted Computer System Evaluation Criteria (TCSEC). Over the span os seven years, the project was transformed into an effort to develop and deploy a product: the Standard Mail Guard (SMG). Since the project took place under a US government contract, the development team needed to maintain detailed records of the time spent on the project. The records from 1987 to 1992 have been combined with information about software code size and error detection. This information has been used to examine the practical impacts of high assurance techniques on a large-scale software development program. Tasks are associated with the A1 formal assurance requirements added approximately 58% to the development cost of security-critical software. In exchange for these costs, the formal assurance tasks (formal specifications, proofs, and specification code correspondence) uncovered 68% of the security flaws detected in LOCK's critical security mechanisms. However, a study of flaw detection during the SMG program found that only 14% of all flaws detected were of the type that could be detected using formal assurance, and that the work of the formal assusrance team only accounted for 19% of all flaws detected. While formal assurance is clearly effective at detecting flaws, its practicality hinges on the degree to which the formally modeled system properties represent all of a system's esential properties.
38459829
Mandatory protection for Internet server software
Server software on the Internet is today's high point for software at risk. Ongoing reports of security flaws suggest that conventional Internet server software packages are intrinsically vulnerable to "server overrun", an attack that subverts the server's behavior and causes it to run attack code instead. The attack code then penetrates other portions of the server host or site unless there are additional defenses. Mandatory protection mechanisms, like those developed for multilevel security applications, can limit the risks of server overrun to a site. Commercial systems have been developed that use three distinct mechanisms: Unix "chroot" isolation, multilevel security (MLS), and type enforcement. The paper compares and contrasts these three mechanisms for server protection.
226549
Using type enforcement to assure a configurable guard
Prior to the introduction of guard systems for electronic mail, guards tended to be overly specialized and not versatile enough for today's user community. The paper examines the use of type enforcement to create a highly assured yet administrator configurable guard. The administrator must be able to trust that the configuration provided will indeed be followed. This occurs by using highly assured or trusted components. These trusted components are then linked together via type enforcement to form a pipeline, with one input channel for data to enter the guard, and one separate, connected output channel for data to exit the guard. These channels are connected via assured processes whose behavior is restricted by the type enforcement mechanism. Furthermore, type enforcement is also used to isolate many components of the guard, which simplifies the assurance arguments. This technology is applied in the latest operational guards developed by the Secure Computing Corporation.
2351489
An Empirical Study Using Task Assignment Patterns to Improve the Accuracy of Software Effort Estimation
In most software development organizations, there is seldom a one-to-one mapping between software developers and development tasks. It is frequently necessary to concurrently assign individuals to multiple tasks and to assign more than one individual to work cooperatively on a single task. A principal goal in making such assignments should be to minimize the effort required to complete each task. But what impact does the manner in which developers are assigned to tasks have on the effort requirements? This paper identifies four task assignment factors: team size, concurrency, intensity, and fragmentation. These four factors are shown to improve the predictive ability of the well-known intermediate COCOMO cost estimation model. A parsimonious effort estimation model is also derived that utilizes a subset of the task assignment factors and unadjusted function points. For the data examined, this parsimonious model is shown to have goodness of fit and quality of estimation superior to that of the COCOMO model, while utilizing fewer cost factors.
39456630
Technology Introduction in a Systemic Context for IT Project Success
The management of information technology (IT) introduction is a complex, interconnected systemic process. Sub-optimal solutions may result when an enterprise fails to analyse a broad spectrum of worthy solutions, taking a systemic standpoint. The information technologies selected and the means adopted to introduce those technologies, can be crucial to the eventual success or failure of an IT project. In this paper various analyses crucial to the management of change are identified and critically examined. The potential consequences of failure to successfully carry out such analyses are canvassed.
31744347
Undergraduate Software Engineering - An Innovative Degree at Swinburne
In this paper we outline the context for the development of an undergraduate degree in Software Engineering in Australia, reflect on curriculum development ideas relevant to such a degree, and describe aspects of the Computer Science degree at Swinburne which, despite its title, may be viewed as a Software Engineering degree. We emphasise the role of project-based units within the degree.
1589294
A Conceptual-Modeling Approach to Extracting Data from the Web
Electronically available data on the Web is exploding at an ever increasing pace. Much of this data is unstructured, which makes searching hard and traditional database querying impossible. Many Web documents, however, contain an abundance of recognizable constants that together describe the essence of a document’s content. For these kinds of data-rich documents (e.g., advertisements, movie reviews, weather reports, travel information, sports summaries, financial statements, obituaries, and many others) we can apply a conceptual-modeling approach to extract and structure data. The approach is based on an ontology – a conceptual model instance – that describes the data of interest, including relationships, lexical appearance, and context keywords. By parsing the ontology, we can automatically produce a database scheme and recognizers for constants and keywords, and then invoke routines to recognize and extract data from unstructured documents and structure it according to the generated database scheme. Experiments show that it is possible to achieve good recall and precision ratios for documents that are rich in recognizable constants and narrow in ontological breadth.
5111320
Work rhythms: analyzing visualizations of awareness histories of distributed groups
We examined records of minute-by-minute computer activity coupled with information about the location of the activity, online calendar appointments, and e-mail activity. We present a number of visualizations of the data that exhibit meaningful patterns in users' activities. We demonstrate how the patterns vary between individuals and within individuals according to time of day, location, and day of the week. Some patterns augment the schedule information found in people's online calendars. We discuss applications for group coordination (especially across time zones) plus opportunities for future research. In light of the popularity of instant messaging, this research identifies some of the benefits and privacy risks associated with the uses of online presence and awareness information.