Anonymous signer verifiable encrypted signature from bilinear pairing

In this paper we propose and prove the security of the new cryptographic primitive called the Anonymous Signer Verifiable Encrypted Signature (ASVES), joining the idea of the group signature and the verifiable encrypted signature. It satisfies the traditional requirements of the group signature (unforgeability, anonymity, unlinkability, traceability) and the opacity condition known from the verifiable encrypted signatures. The corresponding scheme may be applied for the fair exchange protocols. Our construction is based on bilinear pairings, defined in the Gap Diffie-Hellman groups.