Protecting mobile agents against malicious hosts.

by Sau-Koon Ng.Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.Includes bibliographical references (leaves 100-112).Abstracts in English and Chinese.Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Evolution of the mobile agent paradigm --- p.1Chapter 1.2 --- Terminology --- p.5Chapter 1.3 --- Beneficial aspects --- p.7Chapter 1.3.1 --- Autonomy --- p.7Chapter 1.3.2 --- Client customization --- p.8Chapter 1.3.3 --- Attendant and real time interactions --- p.8Chapter 1.4 --- Fundamental deployment bottleneck: security concern --- p.9Chapter 1.4.1 --- Risking the mobile agent hosts --- p.10Chapter 1.4.2 --- Risking the mobile agents --- p.11Chapter 1.4.3 --- The difficult problem --- p.12Chapter 1.5 --- Contribution of this thesis --- p.13Chapter 1.6 --- Structure of the thesis --- p.14Chapter 2 --- Understanding attacks and defense --- p.15Chapter 2.1 --- Introduction --- p.15Chapter 2.2 --- Understanding attacks --- p.16Chapter 2.2.1 --- The meaning of an attack --- p.16Chapter 2.2.2 --- An abstract model of attacks --- p.17Chapter 2.2.3 --- A survey of various attacks --- p.21Chapter 2.3 --- Understanding defense --- p.25Chapter 2.3.1 --- The meaning of defense --- p.25Chapter 2.3.2 --- Security requirements of defense --- p.26Chapter 2.3.3 --- A survey of protection schemes --- p.28Chapter 2.4 --- Concluding remarks --- p.40Chapter 3 --- Confidentiality in mobile agent systems --- p.42Chapter 3.1 --- Introduction --- p.42Chapter 3.2 --- Motivations --- p.43Chapter 3.2.1 --- Program comprehension --- p.44Chapter 3.2.2 --- Black-box testing --- p.45Chapter 3.3 --- Theory --- p.46Chapter 3.3.1 --- Assumptions --- p.46Chapter 3.3.2 --- Entropy of mobile agents --- p.46Chapter 3.3.3 --- Intention spreading by insertion --- p.49Chapter 3.3.4 --- Intention shrinking by splitting --- p.52Chapter 3.3.5 --- Nested spreading and shrinking --- p.55Chapter 3.4 --- Implementation possibilities --- p.55Chapter 3.4.1 --- Addition of irrelevant variables and conditional statements --- p.55Chapter 3.4.2 --- Splitting the cost function --- p.60Chapter 3.5 --- Security analysis --- p.63Chapter 3.5.1 --- Human inspection --- p.63Chapter 3.5.2 --- Automatic program comprehension --- p.64Chapter 3.6 --- Related work --- p.66Chapter 3.6.1 --- Time limited blackbox security --- p.66Chapter 3.6.2 --- Computing with encrypted function --- p.66Chapter 3.7 --- Applicability --- p.67Chapter 3.8 --- Further considerations --- p.68Chapter 3.8.1 --- Weaknesses --- p.68Chapter 3.8.2 --- Relationship with other approaches --- p.69Chapter 3.8.3 --- Further development --- p.71Chapter 3.9 --- Concluding remarks --- p.71Chapter 4 --- Anonymity in mobile agent systems --- p.73Chapter 4.1 --- Introduction --- p.73Chapter 4.2 --- Solutions to anonymity --- p.74Chapter 4.2.1 --- Mixing --- p.75Chapter 4.2.2 --- Group signatures --- p.76Chapter 4.3 --- Anonymous agents --- p.78Chapter 4.3.1 --- Anonymous connection --- p.78Chapter 4.3.2 --- Anonymous communication --- p.79Chapter 4.4 --- Concluding remarks --- p.84Chapter 5 --- Open issues --- p.86Chapter 5.1 --- Introduction --- p.86Chapter 5.2 --- Security issues --- p.86Chapter 5.2.1 --- Reachable problems --- p.87Chapter 5.2.2 --- Difficult problems --- p.88Chapter 5.3 --- Performance issues --- p.88Chapter 5.3.1 --- Complexity and strength --- p.89Chapter 5.3.2 --- An optimizing protocol --- p.90Chapter 5.4 --- Concluding remarks --- p.94Chapter 6 --- Conclusions --- p.9

XMLFinder : an intelligent agent based on CBR for E-Commerce

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Data Politics

Data has become a social and political issue because of its capacity to reconfigure relationships between states, subjects, and citizens. This book explores how data has acquired such an important capacity and examines how critical interventions in its uses in both theory and practice are possible. Data and politics are now inseparable: data is not only shaping our social relations, preferences and life chances but our very democracies. Expert international contributors consider political questions about data and the ways it provokes subjects to govern themselves by making rights claims. Concerned with the things (infrastructures of servers, devices, and cables) and language (code, programming, and algorithms) that make up cyberspace, this book demonstrates that without understanding these conditions of possibility it is impossible to intervene in or to shape data politics. Aimed at academics and postgraduate students interested in political aspects of data, this volume will also be of interest to experts in the fields of internet studies, international studies, Big Data, digital social sciences and humanities

Annual Report of the University, 1994-1995, Volumes 1-4

DEMONSTRATING THE STRENGTH OF DIVERSITY A walk around the UNM campus as students change classes demonstrates UNM\\u27s commitment to diversity. Students and professors from a variety of ethnic backgrounds crowd the sidewalks and fill classrooms. Over the past year UNM moved forward with existing and new programs to interest more minority students, faculty and staff in the University and to aid in their success while here. Hispanic Outlook in Higher Education recently recognized the University\\u27s endeavors, ranking UNM as one of the best colleges in the nation at graduating Hispanic students. Provost Mary Sue Coleman says diversity contributes to a stimulating environment where faculty and students have different points of view and experiences. The campus becomes a more intellectually alive place, she says. The efforts to build a diverse campus go hand in hand with the University\\u27s goals of achieving academic excellence and attracting the best and brightest. MINORITY ENROLLMENT In the fall of 1994 a total of 32 percent of the student body came from underrepresented groups. The UNM School of Law had the largest number of Native Americans enrolled in any law school in the country

Data Politics: Worlds, Subjects, Rights

Data has become a social and political issue not only because it concerns anyone who is connected to the Internet but also because it reconfigures relationships between states, subjects, and citizens. Just about every device is now connected to the Internet and generating vast quantities of digital traces about interactions, transactions and movements whether users are aware or not. What started as an ostensibly liberated space the Internet rapidly became the space over and through which governments and corporations began collecting, storing, retrieving, analysing, and producing data that analyses what people do and say on the Internet. This ranges from who communicates with whom, who goes where, and who says what – and much more besides. This is now being augmented with data that people produce about themselves, especially their relations, body movements and measurements; the amount and range of data that has become available is, as everyone now knows, staggering. This chapter introduces the main themes of the book to position these developments within a broad historical-sociological perspective and to articulate an international political sociology of data politics

Maritime expressions:a corpus based exploration of maritime metaphors

This study uses a purpose-built corpus to explore the linguistic legacy of Britain’s maritime history found in the form of hundreds of specialised ‘Maritime Expressions’ (MEs), such as TAKEN ABACK, ANCHOR and ALOOF, that permeate modern English. Selecting just those expressions commencing with ’A’, it analyses 61 MEs in detail and describes the processes by which these technical expressions, from a highly specialised occupational discourse community, have made their way into modern English. The Maritime Text Corpus (MTC) comprises 8.8 million words, encompassing a range of text types and registers, selected to provide a cross-section of ‘maritime’ writing. It is analysed using WordSmith analytical software (Scott, 2010), with the 100 million-word British National Corpus (BNC) as a reference corpus. Using the MTC, a list of keywords of specific salience within the maritime discourse has been compiled and, using frequency data, concordances and collocations, these MEs are described in detail and their use and form in the MTC and the BNC is compared. The study examines the transformation from ME to figurative use in the general discourse, in terms of form and metaphoricity. MEs are classified according to their metaphorical strength and their transference from maritime usage into new registers and domains such as those of business, politics, sports and reportage etc. A revised model of metaphoricity is developed and a new category of figurative expression, the ‘resonator’, is proposed. Additionally, developing the work of Lakov and Johnson, Kovesces and others on Conceptual Metaphor Theory (CMT), a number of Maritime Conceptual Metaphors are identified and their cultural significance is discussed