Systems and Security Modelling: From Theory to Practice (Really) by Professor David J. Pym

Abstract: I describe a mathematical systems modelling framework that is motivated by a desire to represent and reason about properties of (large-scale) systems situated in dynamic environments. Motivated by the concepts of distributed systems theory, the framework has at its core mathematical treatments of environment, location, resource, and process, and comes along with a separating modal logic. Extensions to analyze questions in computer security are also considered. The mathematical structures provide a semantics for a modelling tool, called (Core) Gnosis, that, together with some elementary utility theory, has been deployed in a range of commercial projects undertaken with Hewlett-Packard’s information security business and its customers. I conclude by discussing the rôle of economics in the context of modelling questions in information security.




Biography:

Professor David J. Pym, 6th Century Chair in Logic, and SICSA Professor of Computing Science, Head of School of Natural and Computing Sciences, University of Aberdeen. Previously Principal Scientist at HP Labs, Bristol and Professor of Logic & Computation at Bath, Professor of Logic at QMUL. PhD Edinburgh; MA, ScD Cambridge; FIMA, FBCS.

Led the ‘Security Analytics’ project at HP Labs, now deployed commercially by Hewlett-Packard in its information security business. One of the designers of the Core Gnosis tool for systems and security modelling which is used to deliver the modelling part of Security Analytics. See this recent news piece about my colleagues at HP: http://www.hpl.hp.com/news/2011/oct-dec/security_analytics.html


David is currently interested in the following areas:


  • Mathematical systems modelling, using algebraic, logical, and stochastic methods, with applications in information security;
  • Topics related to the economics of information security;
  • Topics related to the economics of systems thinking;
  • Topics connecting logic (substructural, modal; process algebra) and utility theory;
  • Topics in logic related to information flow and trust domains;
  • Topics related to information security, information stewardship, and cloud computing;
  • Topics in logic related to the theory of search spaces.

Event details

  • When: 24th October 2011 14:00 - 15:00
  • Where: Phys Theatre C
  • Series: CS Colloquia Series
  • Format: Colloquium

The Dependability of Complex Socio-technical Infrastructure & Smart Grids and Smart Meters: Game Changer, or Serious Danger? by Prof. Ross Anderson

DLS Programme

Lecture 1: The Dependability of Complex Socio-technical Infrastructure

Abstract: We have all become dependent on large complex systems such as Facebook, the bank payment system and even the Internet itself.

Keeping these systems dependable in the face of accidents, errors and malice is one of the most important, and interesting, challenges facing engineers today. It brings not only technical problems of the highest order, but also some intricate economics; how do we persuade firms to invest in spare capacity that will mostly help their competitors offer better service? I’ll discuss such problems in two contexts: frauds against payment networks, and the resilience of the Internet. The talk will draw on a recent major study we did for ENISA of the resilience of the Internet interconnect.

Continue reading

Event details

  • When: 5th December 2011 13:30 - 17:00
  • Where: Purdie Theatre B
  • Series: Distinguished Lectures Series

Learning hard chart constraints for efficient context-free parsing by Brian Roark – Oregon Health & Science University

Abstract: In this talk, I’ll present some recent work in learning hard constraints for cells within a context-free parsing chart, to reduce parsing time. Each cell in the chart represents one of the O(n^2) substrings of the input string, and characteristics of each substring can be used to decide how much work to do in the associated chart cell. I’ll discuss finite-state models for tagging chart constraints on words, including methods for bounding the worst-case complexity of the parsing pipeline to quadratic or sub-quadratic in the length of the string. Empirical results will be presented for English and Chinese, achieved by constraining various high accuracy parsers.

Finally, I will present a generalization of these finite-state approaches that performs a quadratic number of classifications (one for each substring) to produce further (finer) constraints on the amount of processing within each cell. This latter approach has the nice property of being trained on maximum likelihood parses, rather than reference parses, making for a straightforward method for tuning parsing efficiency to new tasks and domains.

Continue reading

Event details

  • When: 27th September 2011 13:00 - 14:00
  • Where: Cole 1.33
  • Series: CS Colloquia Series
  • Format: Colloquium

Exploring semantics in situation identification using context lattices by Dr.Juan Ye

Pervasive systems must offer an open, extensible, and evolving portfolio of services which integrate sensor data from a diverse range of sources. The core challenge is to provide appropriate and consistent adaptive behaviours for these services in the face of huge volumes of sensor data exhibiting varying degrees of precision, accuracy and dynamism. Situation identification is an enabling technology that resolves noisy sensor data and abstracts it into higher-level concepts that are interesting to applications. 

In this talk, I will provide a comprehensive analysis of the nature and characteristics of situations, discuss the complexities of situation identification, and introduce a novel situation identification technique called “context lattice”. The context lattice is built on a sound mathematical model, aiming to identify situations by systematically exploring the semantics of sensor data, domain knowledge, and situations in a pervasive computing system. I will present and discuss the evaluation results when applying this technique to recognising human activities in smart home environments. This talk will be concluded with challenging questions in the area of situation identification.
Continue reading

Event details

  • When: 3rd October 2011 14:00 - 15:00
  • Where: Cole 1.33
  • Series: CS Colloquia Series
  • Format: Colloquium