A new tree-structure-specified multisignature scheme for a document circulation system

In this paper, the authors propose a new multisignature scheme with pairing-based cryptography, which can describe the tree structure of signers. In order to denote the relationship among a parent and its child signers, a dedicated middle key is generated on our scheme. In addition, we prove that our scheme is provably secure under the Gap-Diffie-Hellman assumption. Based on our proposal, we also implement the prototype of a document circulation system. In this system, a document is signed by members, who are divided into multiply layered groups. The browsing history can be confirmed by verifying the final signature on the document. The computational performance of the system is evaluated, and the result shows a good performance.