Abstract
A key distribution scheme for dynamic conferences is a method by which initially an (off-line) trusted server distributes private individual pieces of information to a set of users. Later any group of users of a given size (a dynamic conference) is able to compute a common secure key. In this paper we study the theory and applications of such perfectly secure systems. In this setting, any group of t users can compute a common key by each user computing using only his private piece of information and the identities of the other t — 1 group users. Keys are secure against coalitions of up to k users, that is, even if k users pool together their pieces they cannot compute anything about a key of any t-size conference comprised of other users. First we consider a non-interactive model where users compute the common key without any interaction. We prove a lower bound on the size of the user’s piece of information of (formula presented) times the size of the common key. We then establish the optimality of this bound, by describing and analyzing a scheme which exactly meets this limitation (the construction extends the one in [2]). Then, we consider the model where interaction is allowed in the common key computation phase, and show a gap between the models by exhibiting an interactive scheme in which the user’s information is only k +1 — 1 times the size of the common key. We further show various applications and useful modifications of our basic scheme. Finally, we present its adaptation to network topologies with neighborhood constraints.
Original language | English |
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Title of host publication | Advances in Cryptology — CRYPTO 1992 - 12th Annual International Cryptology Conference, Proceedings |
Editors | Ernest F. Brickell |
Publisher | Springer Verlag |
Pages | 471-486 |
Number of pages | 16 |
ISBN (Print) | 9783540573401 |
DOIs | |
State | Published - 1993 |
Externally published | Yes |
Event | 12th Annual International Cryptology Conference, CRYPTO 1992 - Santa Barbara, United States Duration: 16 Aug 1992 → 20 Aug 1992 |
Publication series
Name | Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) |
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Volume | 740 LNCS |
ISSN (Print) | 0302-9743 |
ISSN (Electronic) | 1611-3349 |
Conference
Conference | 12th Annual International Cryptology Conference, CRYPTO 1992 |
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Country/Territory | United States |
City | Santa Barbara |
Period | 16/08/92 → 20/08/92 |
Bibliographical note
Publisher Copyright:© Springer-Verlag Berlin Heidelberg 1993.
Funding
* Partially supported by Italian Ministry of University and Research (M.U.R.S.T.) and by National Council for Research (C.N.R.) under grant 91.02326.CT12. E.F. Bnckell (Ed.): Advances in Cryptology - CRYPT0 '92, LNCS 740, pp. 471-486, 1993. 0 Spnnger-Verlag Berlin Heidelberg 1993
Funders | Funder number |
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C.N.R. | 91.02326 |
M.U.R.S.T. | |
Ministry of University and Research | |
National Council for Research |