Identity Based Aggregate Signcryption Schemes

An identity-based signature scheme allows any pair of users to communicate securely and to verify each others signatures without exchanging public key certificates. For achieving both confidentiality and authenticity simultaneously, signcryption schemes are used. An aggregate signature scheme is a digital signature scheme that supports aggregation of individual signatures. Given n signatures on n distinct messages signed by n distinct users, it is possible to aggregate all these signatures into a single signature. This signature will convince the verifier that all the n signers have signed the corresponding n messages. In this paper, we introduce the concept of aggregate signcryption which achieves confidentiality, authentication and aggregation efficiently. This helps in improving the communication and the computation efficiency. Also, we extend the scheme to achieve public verifiability with very efficient aggregate verification, that uses fixed number of pairings.