Open are open source systems more dependable its are

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Unformatted text preview: ms more dependable? It’s Are easier for the attackers to find vulnerabilities, but also easier for the defenders to find and fix them also Theory: openness helps both equally if bugs are Theory: random in standard dependability model random So maybe we should keep systems closed So (Rescorla) – but this is an empirical question (Rescorla) So get the statistics: bugs are correlated in a So number of real systems (‘Milk or Wine?’) number Trade-off: the gains from this, versus the risks to Trade-off: systems whose owners don’t patch systems Vulnerability Markets Vulnerability Security isn’t just a lemons market – even the Security vendor often doesn’t know the quality of his software software Insurance can be problematic because of interfirm failure correlation Camp and Wolfram (2000), Schechter (2002): try Camp vulnerability markets vulnerability Two traders now exist (but prices secret) Alternatives - software quality derivatives Alternatives (Böhme), bug auctions (Ozment) (Böhme), How Much to Spend? How How much should firms spend on information How security? security? Governments, vendors say: much much more Governments, than at present (But they’ve been saying this for 20 years!) 20 Measurements of security return-on-investment Measurements suggest current expenditure may be about right suggest But SMEs spend too little, big firms too much, But and governments way too much and Adams: it’s the selection of the risk managers Games on Networks Games The topology of a network can be important! Barabási and Albert showed that a scale-free Barabási network could be attacked efficiently by targeting its high-order nodes its Think: rulers target Saxon landlords / Ukrainian Think: kulaks / Tutsi schoolteachers /… kulaks Can we use evolutionary game theory ideas to Can figure out how networks evolve? figure Idea: run many simulations between different Idea: attack / defence strategies attack Games on Networks (2) Games Vertex-order attacks with: Black – normal (scalefree) node free) replenishment replenishment Green – defenders Green replace high-order nodes with rings nodes Cyan – they use Cyan cliques (c.f. system biology …)...
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This document was uploaded on 01/14/2014.

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