{"id":6424,"date":"2026-04-29T18:24:08","date_gmt":"2026-04-30T01:24:08","guid":{"rendered":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/?p=6424"},"modified":"2026-04-29T18:24:08","modified_gmt":"2026-04-30T01:24:08","slug":"requalizer-a-co-designed-information-flow-control-and-quality-of-service-management-framework","status":"publish","type":"post","link":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/2026\/04\/29\/requalizer-a-co-designed-information-flow-control-and-quality-of-service-management-framework\/","title":{"rendered":"Requalizer: A Co-designed Information Flow Control and Quality of Service Management Framework"},"content":{"rendered":"<p>Kumseok Jung, Sathish Gopalakrishnan, Karthik Pattabiraman, To appear in the Proceedings of the <a href=\"https:\/\/middleware-conf.github.io\/2026\/\">ACM\/IFIP\/Usenix International Middleware Conference (Middleware)<\/a>, 2026. (Acceptance rate: TBD). [ <a href=\"https:\/\/www.dropbox.com\/scl\/fi\/bg5kmxb2tmqp1y178lv92\/middleware26-requalizer.pdf?rlkey=puvybjy8ezlctlqn2sdjp2vlj&#038;st=2qldw6dm&#038;dl=0\">PDF<\/a> | Talk ] (Code)<br \/>\n<!--more--><br \/>\n<strong>Abstract: <\/strong> Modern distributed applications must satisfy complex security and privacy (S&#038;P) requirements, while simultaneously meeting quality of service (QoS) goals. Dynamic information flow tracking (DIFT) is a powerful mechanism for enforcing fine-grained S&#038;P policies. However, integrating DIFT with conventional distributed computing platforms (DCP) creates a fundamental conflict. Layered approaches suffer from prohibitive runtime overheads, and standard QoS mechanisms &#8212; such as dynamic replication &#8212; can silently break the protections provided by DIFT by replicating a sensitive service to untrusted nodes.<\/p>\n<p>To resolve this, we introduce Requalizer, a framework that co-designs QoS management and DIFT. Requalizer employs a dataflow-aware workload placement strategy that creates topologically isolated pipelines, allowing the system to safely disable expensive runtime tracking for internal flows. Furthermore, we formulate a DIFT-aware load balancer using Mixed-Integer Linear Programming (MILP), guaranteeing that routing decisions optimize performance without violating non-interference rules.<\/p>\n<p>We evaluated Requalizer using three applications. Our results show that Requalizer reconciles these competing goals, incurring only 3% latency overhead compared to a non-secure baseline while maintaining 100% policy compliance where layered approaches do not. Further, Requalizer maintains 100% policy compliance even under node failures and network congestion.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Kumseok Jung, Sathish Gopalakrishnan, Karthik Pattabiraman, To appear in the Proceedings of the ACM\/IFIP\/Usenix International Middleware Conference (Middleware), 2026. (Acceptance rate: TBD). [ PDF | Talk ] (Code)<\/p>\n","protected":false},"author":10348,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[81],"tags":[64,4,46,9,22,12],"class_list":["post-6424","post","type-post","status-publish","format-standard","hentry","category-talks","tag-64","tag-conference","tag-edge","tag-iot","tag-kumseok","tag-security"],"_links":{"self":[{"href":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/wp-json\/wp\/v2\/posts\/6424","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/wp-json\/wp\/v2\/users\/10348"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/wp-json\/wp\/v2\/comments?post=6424"}],"version-history":[{"count":1,"href":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/wp-json\/wp\/v2\/posts\/6424\/revisions"}],"predecessor-version":[{"id":6425,"href":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/wp-json\/wp\/v2\/posts\/6424\/revisions\/6425"}],"wp:attachment":[{"href":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/wp-json\/wp\/v2\/media?parent=6424"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/wp-json\/wp\/v2\/categories?post=6424"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.ubc.ca\/dependablesystemslab\/wp-json\/wp\/v2\/tags?post=6424"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}