{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/109512"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/109512","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Scheduler side-channels in preemptive real-time systems: attack and defense techniques","abstract":"Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2022-12-01","abstract_html":"Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2022-12-01","abstract_has_math":false,"creators":["Chen, Chien-Ying"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Computer Science","degree_department":null,"school":null,"contributors":["Mohan, Sibin","Nahrstedt, Klara","Borisov, Nikita","Bobba, Rakesh B.","Pellizzoni, Rodolfo"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2021,"date_issued":"2021-03-05T21:42:43Z","date_published":"2021-03-05T21:42:43Z","updated_at":"2026-07-22T22:24:50Z","subjects":["Scheduler Side-Channels","Real-Time Systems","RTS"],"languages":["en"],"rights":["Copyright 2020 Chien-Ying Chen"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/109512","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Mohan, Sibin","Nahrstedt, Klara","Borisov, Nikita","Bobba, Rakesh B.","Pellizzoni, Rodolfo"]},{"key":"dc:creator","label":"Author","values":["Chen, Chien-Ying"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2021-03-05T21:42:43Z","2023-03-05T21:43:00Z","2020-11-30","2020-12"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Computer Science"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Scheduler Side-Channels","Real-Time Systems","RTS"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2020 Chien-Ying Chen"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/109512"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2022-12-01","The student, Chien-Ying Chen, accepted the attached license on 2020-11-30 at 03:44.","The student, Chien-Ying Chen, submitted this Dissertation for approval on 2020-11-30 at 03:57.","This dissertation aims to address the problem of the side-channels caused by the deterministic nature embedded in the real-time schedulers in preemptive real-time systems (RTS). The dissertation explores the problem by postulating that there exist timing-based side-channels (i.e., scheduler side-channels) that enable adversaries to gauge the behavior of the system with high precision in preemptive RTS and that the RTS can be protected by diversifying the real-time schedules. To validate this hypothesis, the work is divided into three groups to tackle the following three key challenges: • Validate the presence of the scheduler side-channels in preemptive RTS. • Protect the RTS by diversifying the real-time schedule. • Evaluate the risks against the scheduler side-channels and the efficacy of a defense scheme. The dissertation shows that the scheduler side-channels exist in both classes of widely used preemptive RTS (i.e., fixed-priority RTS and dynamic-priority RTS) and can leak critical task information using a user-space, non-privileged task. Such information can be leveraged by other collaborative attacks (e.g., advanced persistent threat attacks) to pose a serious threat to systems. A study on the schedule randomization technique as a defense strategy is conducted and shows that, while being effective in disturbing the repeated patterns in the schedule, there exist trade-offs (e.g., the scheduling overhead) and shortcomings (e.g., ineffectiveness in the face of real-time constraints.) Based on the lesson learned, the dissertation introduces the notion of “schedule indistinguishability” and presents a defense scheme that provides security guarantees to critical tasks by achieving the schedule indistinguishability. The scheduler relaxes the real-time constraints and add random noise drawn from bounded Laplace distribution to the task’s execution patterns to hide the repeated patterns from the task schedule. The dissertation further introduces a security evaluation framework consisting of diverse metrics that capture the unique characteristics of real-time schedules and scheduler side-channels to better evaluate the risks for a given RTS. The work is concluded by assessing the developed scheduler against scheduler side-channels with using the introduced security evaluation framework.","This Dissertation was approved for publication on 2020-11-30 at 14:53.","DSpace SAF Submission Ingestion Package generated from Vireo submission #15981 on 2021-03-04 at 16:20:00","Made available in DSpace on 2021-03-05T21:42:43Z (GMT). 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The dissertation explores the problem by postulating that there exist timing-based side-channels (i.e., scheduler side-channels) that enable adversaries to gauge the behavior of the system with high precision in preemptive RTS and that the RTS can be protected by diversifying the real-time schedules. To validate this hypothesis, the work is divided into three groups to tackle the following three key challenges: • Validate the presence of the scheduler side-channels in preemptive RTS. • Protect the RTS by diversifying the real-time schedule. • Evaluate the risks against the scheduler side-channels and the efficacy of a defense scheme. The dissertation shows that the scheduler side-channels exist in both classes of widely used preemptive RTS (i.e., fixed-priority RTS and dynamic-priority RTS) and can leak critical task information using a user-space, non-privileged task. Such information can be leveraged by other collaborative attacks (e.g., advanced persistent threat attacks) to pose a serious threat to systems. A study on the schedule randomization technique as a defense strategy is conducted and shows that, while being effective in disturbing the repeated patterns in the schedule, there exist trade-offs (e.g., the scheduling overhead) and shortcomings (e.g., ineffectiveness in the face of real-time constraints.) Based on the lesson learned, the dissertation introduces the notion of “schedule indistinguishability” and presents a defense scheme that provides security guarantees to critical tasks by achieving the schedule indistinguishability. The scheduler relaxes the real-time constraints and add random noise drawn from bounded Laplace distribution to the task’s execution patterns to hide the repeated patterns from the task schedule. The dissertation further introduces a security evaluation framework consisting of diverse metrics that capture the unique characteristics of real-time schedules and scheduler side-channels to better evaluate the risks for a given RTS. The work is concluded by assessing the developed scheduler against scheduler side-channels with using the introduced security evaluation framework.","This Dissertation was approved for publication on 2020-11-30 at 14:53.","DSpace SAF Submission Ingestion Package generated from Vireo submission #15981 on 2021-03-04 at 16:20:00","Made available in DSpace on 2021-03-05T21:42:43Z (GMT). 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