SSAATRIASVRNovel Classes of Side Channelsand Covert ChannelsDissertation zur Erlangung des Grades desDoktors der Ingenieurwissenschaftender Naturwissenschaftlich-Technischen Fakult¨atender Universit¨at des SaarlandesThesis for obtaining the title of Doctor of Engineeringof the Faculties of Natural Sciences and Technologyat Saarland UniversityMarkus Du¨rmuthSaarbru¨cken, 2009IEEVNISNIUSKolloquium: 23. Dezember 2009Dekan: Prof. Dr. Joachim WeickertPru¨fungsausschuss: Prof. Dr. Dr. h.c. mult. Reinhard WilhelmProf. Dr. Michael BackesDr. Dominique UnruhDr. Jan SchwinghammerAbstractWhen assessing the security of security-critical systems, it is crucial to con-sider conceptually new attacks, as appropriate countermeasures can only be im-plemented against known threats. Consequently, in this thesis we explore newclasses of attacks and evaluate countermeasures.Ourcontributionisthree-fold. Weidentifytwopreviouslyunknownsidechan-nel attacks, i.e., attacks that exploit unintended information leakage. First, weconsider optical emanations, i.e., the unavoidable emanation of every monitor.We demonstrate how to exploit tiny reflections in stationary objects and the hu-man eye, and even diffuse reflections in objects such as the user’s shirt. Second,we study acoustic emanations of dot-matrix printers and show that the printedtext can be reconstructed from a recording of the sound emitted while printing.