Abstract: On-line handwritten signature verification is one kind of biometric identity recognition technology.In this thesis，an on-line handwritten signature verification algorithm using VDDTW is presented.The distance measure of DTW is modified based on VDDTW.The local curve changes among time series elements are considered in order to prevent mistakes，which are produced by using DTW.The result of experiment proves that this algorithm obtains a good verification effect when skilled forgeries are used.

摘要： 在线手写签名认证是一种基于生物特征的身份认证技术。将VDDTW算法应用于在线手写签名认证，该算法改进了DTW中局部匹配距离的计算方法，考虑了时间序列局部曲线的变化趋势，使得时间序列的局部点到点的对正更加合理。在采用有训练的伪造样本的情况下，对累积匹配距离进行时间加权，加大了真伪签名的区分度。实验结果表明了VDDTW算法用于在线签名认证的有效性。