On the optimization of bipartite secret sharing schemes

Optimizing the ratio between the maximum length of the shares and the length of the secret value in secret sharing schemes for general access structures is an extremely difficult and long-standing open problem. In this paper, we study it for bipartite access structures, in which the set of participa...

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Bibliographic Details
Authors: Farras Ventura, Oriol, Metcalf-Burton, Jessica Ruth, Padró Laimon, Carles|||0000-0002-8644-5929, Vázquez González, Leonor
Format: article
Publication Date:2010
Country:España
Institution:Universitat Politècnica de Catalunya (UPC)
Repository:UPCommons. Portal del coneixement obert de la UPC
Language:English
OAI Identifier:oai:upcommons.upc.edu:2117/12185
Online Access:https://hdl.handle.net/2117/12185
https://dx.doi.org/10.1007/978-3-642-14496-7_8
Access Level:Open access
Keyword:Cryptography
Matroids
Linear programming
Criptografia
Matroides
Programació lineal
Àrees temàtiques de la UPC::Matemàtiques i estadística::Investigació operativa::Programació matemàtica
Description
Summary:Optimizing the ratio between the maximum length of the shares and the length of the secret value in secret sharing schemes for general access structures is an extremely difficult and long-standing open problem. In this paper, we study it for bipartite access structures, in which the set of participants is divided in two parts, and all participants in each part play an equivalent role. We focus on the search of lower bounds by using a special class of polymatroids that is introduced here, the bipartite ones. We present a method based on linear programming to compute, for every given bipartite access structure, the best lower bound that can be obtained by this combinatorial method. In addition, we obtain some general lower bounds that improve the previously known ones, and we construct optimal secret sharing schemes for a family of bipartite access structures.