http://www.ecs.soton.ac.uk/seminars/ ECS Seminars and Events Wednesday 18th April 2012
]]> http://www.ecs.soton.ac.uk/seminars/699 Wednesday 25th April 2012
]]> http://www.ecs.soton.ac.uk/seminars/700 Wednesday 25th April 2012
]]> http://www.ecs.soton.ac.uk/seminars/688 Wednesday 2nd May 2012
]]> http://www.ecs.soton.ac.uk/seminars/701 Wednesday 2nd May 2012
The Byzantine Generals is a classic distributed agreement problem with a published, proven but rather complex solution. I'll describe the problem and try to explain the solution published by Lamport, Shostak and Pease in 1982 and add some further observations based on my experiments with an implementation of their algorithm.]]> http://www.ecs.soton.ac.uk/seminars/707 Wednesday 16th May 2012
]]> http://www.ecs.soton.ac.uk/seminars/709 Wednesday 23rd May 2012
]]> http://www.ecs.soton.ac.uk/seminars/710 Wednesday 23rd May 2012
]]> http://www.ecs.soton.ac.uk/seminars/705 Thursday 24th May 2012
Game semantics is a trace-like denotational semantics for programming languages where the notion of legal observable behaviour of a term is defined combinatorially, by means of rules of a game between the term (Proponent) and its context (Opponent). In general, the richer the computational features a language has, the less constrained the rules of the semantic game. In this talk we consider the consequences of taking this relaxation of rules to the limit, by granting the Opponent omnipotence, that is, permission to play any move without combinatorial restrictions. However, we impose an epistemic restriction by not granting Opponent omniscience, so that Proponent can have undisclosed secret moves. We introduce a basic C-like programming language and we define such a semantic model for it. We argue that the resulting semantics is an appealingly simple combination of operational and game semantics and we show how certain traces explain system-level attacks, i.e. plausible attacks that are realizable outside of the programming language itself. We also show how allowing Proponent to have secrets ensures that some desirable equivalences in the programming language are preserved. (joint work with Nikos Tzevelekos, Queen Mary University, London, to appear at MFPS XXVIII)]]> http://www.ecs.soton.ac.uk/seminars/696 Wednesday 30th May 2012
]]> http://www.ecs.soton.ac.uk/seminars/711 Wednesday 30th May 2012
]]> http://www.ecs.soton.ac.uk/seminars/708 Wednesday 13th June 2012
]]> http://www.ecs.soton.ac.uk/seminars/704 Wednesday 20th June 2012
]]> http://www.ecs.soton.ac.uk/seminars/712