基于身份的无可信中心门限环签名方案

已有的多数基于身份的门限环签名方案不能克服密钥托管问题，而能克服密钥托管问题的基于身份的无可信中心签名方案存在效率不高的缺陷。该文利用分布式秘密共享思想和双线性对，提出一个有效的基于身份的无可信中心门限环签名方案。该方案能保证不诚实的PKG无法伪造环签名，有效避免了密钥托管问题。同时该方案只需要2次对运算，比已有的门限环签名方案和无可信中心的基于身份的签名方案效率更高。

ID-based Threshold Ring Signature Scheme Without Trusted Party

Most previous ID-based threshold ring signatures cannot give over the problem of key escrow. Whereas, the ID-based ring signatures which can get over the problem of key escrow have some drawback of low efficiency. In this paper, the thought of distributed secret sharing and bilinear parings are adopted, and an efficient ID-based threshold ring signature scheme without a trusted party is proposed. The proposed scheme can ensure that the dishonest Private Key Generator(PKG) cannot impersonate the ring members to sign a message. The problem of key escrow can be avoided availably. The proposed scheme only needs two bilinear parings. It is more efficient than the previous schemes of ID-based threshold ring signature and ID-based signature without trusted party.