An ID-based signcryption scheme with compartmented secret sharing for unsigncryption

In this paper the ID-based signcryption scheme of Li, Xin, and Hu is extended to a compartmented scheme. If an organization is partitioned into different compartments, this scheme allows any member of a specific compartment to participate in the unsigncryption; moreover, each member of a compartment has information unique to that individual. This construction is the first (to the authors' knowledge) to combine identity-based encryption, Shamir's threshold scheme, and signcryption into an implementable compartmented sharing scheme.