International Association for Cryptologic Research (IACR)
Abstract
A secret sharing scheme starts with a secret and then derives from it
certain shares (or shadows) which are distributed to users.
The secret may be recovered only by certain
predetermined groups. In case of compartmented secret sharing, the
set of users is partitioned into compartments and the secret
can be recovered only if the number of participants from
any compartment is greater than a fixed compartment threshold
and the total number of participants is greater than a global threshold.
In this paper we present a new compartmented secret sharing scheme by
extending the Brickell\u27s construction to the case that the global threshold
is strictly greater than the sum of the compartment thresholds and we
indicate how to use the threshold secret sharing schemes
based on the Chinese remainder theorem in order to decrease the size of shares