An Efficient and Publicly Verifiable Id-Based Multi-Signcryption Scheme.

link: http://arxiv.org/abs/0909.1412
Abstract

Multi-signcryption is used when different senders wants to authenticate a
single message without revealing it. This paper proposes a multi signcryption
scheme in which no pairing is computed on the signcryption stage and the
signatures can be verified publicly.