Jon Crowcroft

What we got wrong with IP

Paraphrasing W. Churchill, one might say "The Internet - the worst network architecture, except for all the rest". In this talk, I will look at some of the design mistakes (assuming that the Internet was actually designed, rather than discovered, like Tigger and Piglet finding the North Pole), that were made in the selection of algorithms and techniques in the lower levels of the Internet. The talk will be structured around 20 key problems (well 23, in fact, for readers of the Illuminati trilogy), and will take in alternative solutions, and their relative merits and tradeoffs. Specific areas of concern are pretty much everything, including naming, addressing, routing, reliability and security, as well as manageability and scaling. At the end of the talk there will be time for questions, but probably not for answers.

Margaret Burnett

End-user Software Engineering

Tools and environments to enable end users to "program" are becoming increasingly popular. The best known such environment is the spreadsheet, and the way users program in this type of environment is by providing formulas. In this talk, we will consider what happens when we add to end-user programming environments consideration of elements of the software engineering lifecycle beyond coding. Doing so seems necessary, because there is ample evidence that end users' programs are no more reliable than those written by professional software engineers. My colleagues and I have been developing a holistic approach to software engineering for end users. It incorporates support for testing, finding bugs, maintenance, and requirements specification. The software engineering knowledge needed is in the system, and the user is not expected to develop expertise at software engineering; instead, the strategy is for the system to provide guidance to the user. In the talk, I will focus primarily on how testing is supported in our approach through a methodology we term the "What You See Is What You Test (WYSIWYT)" methodology.

Markus Kuhn


Electromagnetic Eavesdropping on Computers

The traditional techniques for remote unauthorized access to private and confidential information -- tapping communication links, code breaking, impersonation -- become increasingly infeasible as the use of modern cryptographic protection techniques proliferates. Those in the business of obtaining information from other people's computers without consent -- criminals and spies, intelligence agency and law enforcement technicians, private detectives, market researchers -- are therefore increasingly looking for alternative eavesdropping techniques. One class of alternatives utilises those unintentional information leaks caused by the physical/analog underlying process in computers and peripherals that can be sensed, amplified and decoded at a distance. This talk provides an introduction, overview and demonstration of electromagnetic passive eavesdropping techniques for personal computers, focusing in particular on video display units. It will present new techniques for eavesdropping liquid-crystal and cathode-ray tube displays and will discuss the information-security threat posed by these, along with simple new protective measures.

Russell Prue


me-learning - mobile electronic learning, future or present?

Richard Gibbens

Performance Modelling of Enterprise IP Networks

This talk presents a new approach to modelling end-to-end performance for IP networks. Unlike earlier models, in which end stations generate traffic at a constant rate, the work discussed here takes the adaptive behaviour of TCP/IP into account. The approach is based on a fixed-point method which determines packet loss, link utilization and TCP throughput across the network. Results are presented for an IP backbone network, which highlight how this new model finds the natural operating point for TCP traffic loads, dependent on route lengths (via round-trip times and number of resources), end-to-end packet loss and the number of user sessions.