Evolving ramp secret-sharing schemes

Amos Beimel, Hussien Othman

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

7 Scopus citations

Abstract

Evolving secret-sharing schemes, introduced by Komargodski, Naor, and Yogev (TCC 2016b), are secret-sharing schemes in which the dealer does not know the number of parties that will participate. The parties arrive one by one and when a party arrives the dealer gives it a share; the dealer cannot update this share when other parties arrive. Komargodski and Paskin-Cherniavsky (TCC 2017) constructed evolving a· i -threshold secret-sharing schemes (for every 0 < a< 1), where any set of parties whose maximum party is the i-th party and contains at least ai parties can reconstruct the secret; any set such that all its prefixes are not an a-fraction of the parties should not get any information on the secret. The length of the share of the i-th party in their scheme is O(i4log i). As the number of parties is unbounded, this share size can be quite large. In this work we suggest studying a relaxation of evolving threshold secret-sharing schemes; we consider evolving (a, b)-ramp secret-sharing schemes for 0 < b< a< 1. Again, we require that any set of parties whose maximum party is the i-th party and contains at least ai parties can reconstruct the secret; however, we only require that any set such that all its prefixes are not a b-fraction of the parties should not get any information on the secret. For all constants 0 < b< a< 1, we construct an evolving (a, b)-ramp secret-sharing scheme where the length of the share of the i-th party is O(1). Thus, we show that evolving ramp secret-sharing schemes offer a big improvement compared to the known constructions of evolving a· i -threshold secret-sharing schemes.

Original languageEnglish
Title of host publicationSecurity and Cryptography for Networks - 11th International Conference, SCN 2018, Proceedings
EditorsDario Catalano, Roberto De Prisco
PublisherSpringer Verlag
Pages313-332
Number of pages20
ISBN (Print)9783319981123
DOIs
StatePublished - 1 Jan 2018
Event11th International Conference on Security and Cryptography for Networks, SCN 2018 - Amalfi, Italy
Duration: 5 Sep 20187 Sep 2018

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume11035 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference11th International Conference on Security and Cryptography for Networks, SCN 2018
Country/TerritoryItaly
CityAmalfi
Period5/09/187/09/18

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