A Strong Designated Verifier Ring Signcryption Scheme

In this paper, we present a new concept of a strong designated verifier ring signcryption scheme. We argue that this is an important cryptographic primitive that can be used to protect privacy and authenticity of a collection of users who are connected through an ad-hoc network, such as Blue tooth.And,the proposed scheme provides a way that leaks authoritative secrets to only a designated person anonymously by one of the group members and no one knows that the secret is from a group member or the recipient, except the recipient.This cryptographic primitive can be used in an anonymous E-Prosecution.It can effectively protect an informant for his/her identity is ambiguous.lt can also guarantee the security of prosecution contents because all prosecutions are encrypted ,non-transferable and can´t be forged.We also present an efficient strong designated verifier ring signcryption scheme based on bilinear pairing.Through cryptanalysis,our scheme is anonymous,nontransferable,indistinguishable under chosen plaintext attack, and unforgeable.