Ideal Hierarchical Secret Sharing Schemes

The search of efficient constructions of ideal secret sharing schemes for families of nonthreshold access structures that may have useful applications has attracted a lot of attention. Several proposals have been made for access structures with hierarchical properties, in which the participants are distributed into levels that are hierarchically ordered. Here, we study hierarchical secret sharing in all generality by providing a natural definition for the family of the hierarchical access structures. Specifically, an access structure is said to be hierarchical if every two participants can be compared according to the following natural hierarchical order: whenever a participant in a qualified subset is substituted by a hierarchically superior participant, the new subset is still qualified. We present a complete characterization of the ideal hierarchical access structures, that is, the ones admitting an ideal secret sharing scheme. We use the well known connection between ideal sec...

• Type: Conference
• Year: 2010
• Where: TCC
• Authors: Oriol Farràs, Carles Padró
• Keywords: Cryptography, Hierarchical Secret Sharing, Ideal Hierarchical Access, Ideal Secret Sharing, TCC 2010