中文摘要：

为了保护签名接收者的隐私，有向签名方案要求签名的验证必须得到接收者或签名者的合作．利用椭圆曲线上双线性映射的基于身份的密码体制，提出了一个公平的基于身份的有向签名方案．当签名者与验证者发生争议时，在二者的协助下，可信第三方能够进行公开验证签名．结果的分析表明，所提方案与同类方案相比签名长度更短并且通信代价更小．

英文摘要：

In order to protect the privacy of the signature receiver in applications, directed signature schemes have the property that the signature can be verified only with the help of the signature receiver of the signer. A directed signature scheme based on identity with fairness is proposed by bilinear maps on elliptic curve cryptosystern based on identity. When the signer and the verifier disputes, trusted third party can check the signature validity with the help of the signer or the designated verifier as well. It is shown our scheme is more efficient and shorter in size than the existing directed signature schemes.