{"schema_version":"0.1","map_id":"paper-28-map","publication_id":28,"publication_anchor":"paper-28","slug":"paper-28","canonical_path":"/knowledge/papers/paper-28/","machine_path":"/knowledge/papers/paper-28.json","root_node_id":"paper-28","stage":"mapped_draft","contribution_type_vocabulary_version":"0.1","contribution_types":["protocol","scheme"],"title":"Communication-Optimal Proactive Secret Sharing for Dynamic Groups","year":2015,"status":"Published","venue":"International Conference on Applied Cryptography and Network Security (ACNS)","topic":"secure-encrypted-computation","labels":["Theory"],"authors":["Joshua Baron","Karim Eldefrawy","Joshua Lampkins","Rafail Ostrovsky"],"keywords":["proactive secret sharing","dynamic groups","communication complexity"],"research_question":"Can proactively protected long-lived secrets move between changing participant sets and thresholds with constant amortized communication per secret, while retaining near-optimal perfect or statistical corruption tolerance?","central_answer":"The paper constructs a dynamic proactive secret-sharing scheme whose Redistribute protocol changes thresholds, refreshes packed polynomial sharings, and transfers them to a new group using batched sharing, hyper-invertible matrices, and error correction; it also sketches dynamic proactive MPC by redistributing between circuit layers.","curation":{"drafted_at":"2026-07-11","drafted_by":[{"actor_type":"ai","name":"OpenAI Codex","role":"full-text extraction, definition/assumption mapping, evidence linking, and initial assessment"}],"method":"Source-grounded review of the complete 24-page UCLA author-hosted version, including definitions, threshold constraints, four threshold-change cases, refresh/recovery, UC proof appendix, and the DPMPC application. 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Security and optimality claims were mapped from the paper but not independently reproved."}},"sources":[{"id":"source-paper-28-fulltext","type":"scholarly_article","title":"Communication-Optimal Proactive Secret Sharing for Dynamic Groups (author-hosted full version)","url":"/pubs/2015/communication-optimal-proactive-secret-sharing-dynamic-groups.pdf","media_type":"application/pdf","sha256":"ba44ecd33639b11a480cd69d8455eefe3584bce3c14b9ad81e727a10babbfc72","page_count":24,"provenance_category":"author","version_note":"Complete author version; not compared line by line with the ACNS proceedings text or IACR ePrint revision history."},{"id":"source-paper-28-author-origin","type":"author_copy","title":"UCLA author copy","url":"https://web.cs.ucla.edu/~rafail/PUBLIC/188.pdf"},{"id":"source-paper-28-archive","type":"manuscript_archive","title":"IACR ePrint 2015/304","url":"https://eprint.iacr.org/2015/304"},{"id":"source-paper-28-official","type":"publication_record","title":"ACNS 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