Multicast over Mutual Transport Layer Security: A Practical Design for Identity-Bound Group Distribution

Multicast over Mutual Transport Layer Security: A Practical Design for Identity-Bound Group Distribution | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Multicast over Mutual Transport Layer Security: A Practical Design for Identity-Bound Group Distribution Gabriel Tevdos, Nooran Zahmir, Terence Tao, Ashton Zhang, Ziewei Ze This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7736545/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Group communication remains a missing primitive in production deployments that rely on mutual Transport Layer Security. The traditional point-to- point model of mutual authentication provides strong assurances about who is at each end of a connection, yet it scales poorly when a publisher must fan out the same content to thousands of authenticated receivers. Network-layer multicast[1] is rarely available across administrative domains, application-layer overlays are often built as best-effort trees with ad hoc security, and many designs end up replicating the payload per subscriber with separate handshakes, keys, and record layers. This paper investigates how to build multicast semantics[2] while retaining the operational and cryptographic properties that operators expect from mutual Transport Layer Security. We present an architecture that uses mutual authentication exclu- sively for the control plane and for the distribution of short-lived, audience-scoped group keys, while the data plane carries a single copy of the payload per edge and achieves replication with zero-copy fan-out. The result preserves identity-binding and revocation semantics, integrates with existing service meshes and certificate-based identities, and reduces publisher cost by removing redundant record-layer work. We describe the design choices that make this practical: audience definition in terms of verifiable identities rather than opaque channels, key derivation bound to group epochs, exporter-based tie-ins to the mutual Transport Layer Security session without exposing handshake secrets, and regional distributors that terminate authentication but do not see plaintext outside a narrow trust boundary. We implement these as sidecars that attach to existing gateways and propose operational guardrails around cer- tificate rotation, revocation stapling, and churn-aware rekeying[2][3]. We evaluate the approach with a set of synthetic and trace-driven experiments that stress group size, churn, and packet loss. The evaluation focuses on tail latency, publisher CPU cost, rekey convergence, and delivery under adverse conditions. The results indicate that the proposed design retains the safety properties of mutual Transport Layer Security while delivering the throughput characteristics of multicast overlays. Median and tail latencies remain stable as groups scale into the thousands, publisher cost grows sublinearly with the number of receivers, and rekey operations converge deterministically even under heavy membership churn. We conclude that multicast over mutual Transport Layer Security is not an oxymoron but a feasible and useful pattern when the control and data planes are separated, identities are first-class, and group state is managed with short epochs and verifiable updates. Theoretical Computer Science encryption homomorphic encryption cloud computing Full Text Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7736545","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":521860392,"identity":"470a4b9c-cedb-4363-bc87-99a25c396da3","order_by":0,"name":"Gabriel Tevdos","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA30lEQVRIiWNgGAWjYHACAxAhx8/eAGJbEK/FWLLnAIgtQbyWxA03EkA0EVoMjh/e9uFnjl1iw83nVzf8KJBg4G/vTsCv5Uxa8czebcnGjbNzym72AB0mcebsBvxaDuQYM/BuY5Ztls5Ju8ED1GIgkUtAy/k3xox/t9UztkmeSbv5hygtN3KMmXm3HVbskWA/dpsoWyRvPCtmlt123FiCJ4fttoyBBA9Bv/CdT97M+HZbtZz98ePPbr75YyPH396LX4vCATiTBxxBPHiVg4B8A5zJ/oCg6lEwCkbBKBiZAAADG0q029oxlAAAAABJRU5ErkJggg==","orcid":"","institution":"University of California, San Diego","correspondingAuthor":true,"prefix":"","firstName":"Gabriel","middleName":"","lastName":"Tevdos","suffix":""},{"id":521860393,"identity":"2d49d467-c4a6-4930-80fd-2798189eb2df","order_by":1,"name":"Nooran Zahmir","email":"","orcid":"","institution":"University of California, San Diego","correspondingAuthor":false,"prefix":"","firstName":"Nooran","middleName":"","lastName":"Zahmir","suffix":""},{"id":521860394,"identity":"c06479c8-eb84-4880-a9ea-20a91e6e8c6b","order_by":2,"name":"Terence Tao","email":"","orcid":"","institution":"University of California, San Diego","correspondingAuthor":false,"prefix":"","firstName":"Terence","middleName":"","lastName":"Tao","suffix":""},{"id":521860395,"identity":"680c6632-0520-4c28-b752-62b7a26b089c","order_by":3,"name":"Ashton Zhang","email":"","orcid":"","institution":"University of California, San Diego","correspondingAuthor":false,"prefix":"","firstName":"Ashton","middleName":"","lastName":"Zhang","suffix":""},{"id":521860396,"identity":"ca7930dd-8001-4768-a022-da4506b70058","order_by":4,"name":"Ziewei Ze","email":"","orcid":"","institution":"Micron Technology","correspondingAuthor":false,"prefix":"","firstName":"Ziewei","middleName":"","lastName":"Ze","suffix":""}],"badges":[],"createdAt":"2025-09-28 21:54:24","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-7736545/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7736545/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":92459717,"identity":"1856c47d-c190-45a2-b7ef-bc6994bed365","added_by":"auto","created_at":"2025-09-30 03:19:43","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":231964,"visible":true,"origin":"","legend":"","description":"","filename":"paper7.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7736545/v1_covered_e2ee12c6-d9d2-4860-8ad1-1813300f43fe.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003eMulticast over Mutual Transport Layer Security: A Practical Design for Identity-Bound Group Distribution\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"University of California, San Diego","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"encryption, homomorphic encryption, cloud computing","lastPublishedDoi":"10.21203/rs.3.rs-7736545/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7736545/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eGroup communication remains a missing primitive in production deployments that rely on mutual Transport Layer Security. The traditional point-to- point model of mutual authentication provides strong assurances about who is at each end of a connection, yet it scales poorly when a publisher must fan out the same content to thousands of authenticated receivers. Network-layer multicast[1] is rarely available across administrative domains, application-layer overlays are often built as best-effort trees with ad hoc security, and many designs end up replicating the payload per subscriber with separate handshakes, keys, and record layers. This paper investigates how to build multicast semantics[2] while retaining the operational and cryptographic properties that operators expect from mutual Transport Layer Security. We present an architecture that uses mutual authentication exclu- sively for the control plane and for the distribution of short-lived, audience-scoped group keys, while the data plane carries a single copy of the payload per edge and achieves replication with zero-copy fan-out. The result preserves identity-binding and revocation semantics, integrates with existing service meshes and certificate-based identities, and reduces publisher cost by removing redundant record-layer work. We describe the design choices that make this practical: audience definition in terms of verifiable identities rather than opaque channels, key derivation bound to group epochs, exporter-based tie-ins to the mutual Transport Layer Security session without exposing handshake secrets, and regional distributors that terminate authentication but do not see plaintext outside a narrow trust boundary. We implement these as sidecars that attach to existing gateways and propose operational guardrails around cer- tificate rotation, revocation stapling, and churn-aware rekeying[2][3]. We evaluate the approach with a set of synthetic and trace-driven experiments that stress group size, churn, and packet loss. The evaluation focuses on tail latency, publisher CPU cost, rekey convergence, and delivery under adverse conditions. The results indicate that the proposed design retains the safety properties of mutual Transport Layer Security while delivering the throughput characteristics of multicast overlays. Median and tail latencies remain stable as groups scale into the thousands, publisher cost grows sublinearly with the number of receivers, and rekey operations converge deterministically even under heavy membership churn. 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