Eprints of Rényi Institute

How to share secrets simultaneously

Csirmaz, László (2011) How to share secrets simultaneously. (Unpublished)



Each member of a team consisting of n person has a secret. The k out of n simultaneous threshold secret sharing requires that any group of k members should be able to recover the secret of the other n-k members, while any group of k-1 or less members should have no information on the secret of other team members. We show that when all secrets are independent and have size s then each team member must receive a share of size at least (n-k)s, and we present a scheme which achieves this bound. This result shows a significant saving over n independent applications of the k out of n-1 threshold schemes which assigns shares of size (n-1)s to each team member independently of k.

Item Type:Research Paper
Keywords and phrases:simultaneous secret sharing; complexity; threshold scheme; secret sharing; interpolation
Subjects:26C99 Polynomials, rational functions - other
94A62 Authentication and secret sharing
Divisions:Research Groups > Theoretical cryptography
Last Modified:20 Jul 2011 13:00

Repository Staff Only: item control page