{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/95490"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/95490","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"A study of covert queueing channels in shared schedulers","abstract":"We study covert queueing channels (CQCs), which are a kind of covert timing channel that may be exploited in shared queues across supposedly isolated users. In our system model, a user modulates messages to another user via his pattern of access to the shared resource. One example of such a channel is the cross-virtual network covert channel in data center networks resulting from the queueing effects of the shared resource. First, we study a system comprising a transmitter and a receiver that share a deterministic and work-conserving first-come-first-served scheduler, and we compute the maximum reliable data transmission rate, i.e., the capacity, of this channel. Next, we extend the model to include a third user who also uses the shared resource and study the effect of the presence of this user on the information transmission rate. The solution approach presented in this extension may be applied to calculate the capacity of the covert queueing channel among any number of users. We also study a queueing covert channel between two users sharing a round robin scheduler. Such a covert channel can arise when users share a resource such as a computer processor or a router arbitrated by a round robin policy. We present an information-theoretic framework to model and derive the capacity of this channel for both noiseless and noisy scenarios. Our results show that seemingly isolated users can communicate at a high rate over the covert channel. Furthermore, we propose a practical finite-length code construction, which achieves the capacity limit.","abstract_html":"We study covert queueing channels (CQCs), which are a kind of covert timing channel that may be exploited in shared queues across supposedly isolated users. In our system model, a user modulates messages to another user via his pattern of access to the shared resource. One example of such a channel is the cross-virtual network covert channel in data center networks resulting from the queueing effects of the shared resource. First, we study a system comprising a transmitter and a receiver that share a deterministic and work-conserving first-come-first-served scheduler, and we compute the maximum reliable data transmission rate, i.e., the capacity, of this channel. Next, we extend the model to include a third user who also uses the shared resource and study the effect of the presence of this user on the information transmission rate. The solution approach presented in this extension may be applied to calculate the capacity of the covert queueing channel among any number of users. We also study a queueing covert channel between two users sharing a round robin scheduler. Such a covert channel can arise when users share a resource such as a computer processor or a router arbitrated by a round robin policy. We present an information-theoretic framework to model and derive the capacity of this channel for both noiseless and noisy scenarios. Our results show that seemingly isolated users can communicate at a high rate over the covert channel. Furthermore, we propose a practical finite-length code construction, which achieves the capacity limit.","abstract_has_math":false,"creators":["Ghassami, Amiremad"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Electrical & Computer Engr","degree_department":null,"school":null,"contributors":["Kiyavash, Negar"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-03-01T16:36:58Z","date_published":"2017-03-01T16:36:58Z","updated_at":"2026-07-22T22:26:37Z","subjects":["Covert Queueing Channel","Capacity Limit","First-Come-First-Served Scheduler","Round Robin Scheduler."],"languages":["en"],"rights":["Copyright 2016 AmirEmad Ghassami"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/95490","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Kiyavash, Negar"]},{"key":"dc:creator","label":"Author","values":["Ghassami, Amiremad"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2017-03-01T16:36:58Z","2019-03-02T10:15:07Z","2016-11-29","2016-12"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical & Computer Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"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":["Covert Queueing Channel","Capacity Limit","First-Come-First-Served Scheduler","Round Robin Scheduler."]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2016 AmirEmad Ghassami"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/95490"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["We study covert queueing channels (CQCs), which are a kind of covert timing channel that may be exploited in shared queues across supposedly isolated users. In our system model, a user modulates messages to another user via his pattern of access to the shared resource. One example of such a channel is the cross-virtual network covert channel in data center networks resulting from the queueing effects of the shared resource. First, we study a system comprising a transmitter and a receiver that share a deterministic and work-conserving first-come-first-served scheduler, and we compute the maximum reliable data transmission rate, i.e., the capacity, of this channel. Next, we extend the model to include a third user who also uses the shared resource and study the effect of the presence of this user on the information transmission rate. The solution approach presented in this extension may be applied to calculate the capacity of the covert queueing channel among any number of users. We also study a queueing covert channel between two users sharing a round robin scheduler. Such a covert channel can arise when users share a resource such as a computer processor or a router arbitrated by a round robin policy. We present an information-theoretic framework to model and derive the capacity of this channel for both noiseless and noisy scenarios. Our results show that seemingly isolated users can communicate at a high rate over the covert channel. Furthermore, we propose a practical finite-length code construction, which achieves the capacity limit.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-12-01","The student, Amiremad Ghassami, accepted the attached license on 2016-11-29 at 03:09.","The student, Amiremad Ghassami, submitted this Thesis for approval on 2016-11-29 at 03:25.","This Thesis was approved for publication on 2016-11-29 at 12:05.","DSpace SAF Submission Ingestion Package generated from Vireo submission #10343 on 2017-02-28 at 14:36:55","Made available in DSpace on 2017-03-01T16:36:58Z (GMT). No. of bitstreams: 2 GHASSAMI-THESIS-2016.pdf: 1740057 bytes, checksum: 265c02de6d87f93fdab7883ecfa5cb71 (MD5) LICENSE.txt: 4214 bytes, checksum: 9d9e0a3d027b29f35695932c5c21e46d (MD5) Previous issue date: 2016-11-29","Embargo set by: Seth Robbins for item 98606 Lift date: 2019-03-01T16:37:19Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 98606 on 2019-03-02T10:15:07Z."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["A study of covert queueing channels in shared schedulers"]}]}],"canonical_facts":{"dc:contributor":["Kiyavash, Negar"],"dc:creator":["Ghassami, Amiremad"],"dc:date":["2017-03-01T16:36:58Z","2019-03-02T10:15:07Z","2016-11-29","2016-12"],"dc:description":["We study covert queueing channels (CQCs), which are a kind of covert timing channel that may be exploited in shared queues across supposedly isolated users. In our system model, a user modulates messages to another user via his pattern of access to the shared resource. One example of such a channel is the cross-virtual network covert channel in data center networks resulting from the queueing effects of the shared resource. First, we study a system comprising a transmitter and a receiver that share a deterministic and work-conserving first-come-first-served scheduler, and we compute the maximum reliable data transmission rate, i.e., the capacity, of this channel. Next, we extend the model to include a third user who also uses the shared resource and study the effect of the presence of this user on the information transmission rate. The solution approach presented in this extension may be applied to calculate the capacity of the covert queueing channel among any number of users. We also study a queueing covert channel between two users sharing a round robin scheduler. Such a covert channel can arise when users share a resource such as a computer processor or a router arbitrated by a round robin policy. We present an information-theoretic framework to model and derive the capacity of this channel for both noiseless and noisy scenarios. Our results show that seemingly isolated users can communicate at a high rate over the covert channel. Furthermore, we propose a practical finite-length code construction, which achieves the capacity limit.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-12-01","The student, Amiremad Ghassami, accepted the attached license on 2016-11-29 at 03:09.","The student, Amiremad Ghassami, submitted this Thesis for approval on 2016-11-29 at 03:25.","This Thesis was approved for publication on 2016-11-29 at 12:05.","DSpace SAF Submission Ingestion Package generated from Vireo submission #10343 on 2017-02-28 at 14:36:55","Made available in DSpace on 2017-03-01T16:36:58Z (GMT). No. of bitstreams: 2 GHASSAMI-THESIS-2016.pdf: 1740057 bytes, checksum: 265c02de6d87f93fdab7883ecfa5cb71 (MD5) LICENSE.txt: 4214 bytes, checksum: 9d9e0a3d027b29f35695932c5c21e46d (MD5) Previous issue date: 2016-11-29","Embargo set by: Seth Robbins for item 98606 Lift date: 2019-03-01T16:37:19Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 98606 on 2019-03-02T10:15:07Z."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/95490"],"dc:language":["en"],"dc:rights":["Copyright 2016 AmirEmad Ghassami"],"dc:subject":["Covert Queueing Channel","Capacity Limit","First-Come-First-Served Scheduler","Round Robin Scheduler."],"dc:title":["A study of covert queueing channels in shared schedulers"],"dc:type":["text"],"thesis:degree_discipline":["Electrical & Computer Engr"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:37Z"}