基于加速度传感器的中文签名身份认证

Chinese signature authentication based on accelerometer

采集用户在签名过程中的三轴加速度信息,可用来实现身份认证。中文签名结构较为复杂,在空中书写的过程难以被模仿,但同时也会使同一用户不同次签名间的差异增大,提高认证难度。传统的二维签名或三维手势认证方法并不能解决这一问题。为了提高中文空中签名身份认证效果,改进了全局序列对齐(GSA)算法,对匹配后的序列进行插值操作。不同于传统GSA算法通过最终匹配分数反映序列间相似度,引入两种距离指标(欧氏距离和绝对值距离)计算序列间的差异。实验结果表明,基于距离指标的两种GSA算法均能提高认证精度,与传统算法相比,二者的系统等误率(EER)分别降低了37.6%和52.6%。

Acceleration data in 3 axes during a signature process can be collected to authenticate users. Because of complex structures of Chinese signature, the process of signing in the air is hard to be forged, but it also increases differences between signatures performed by the same user which brings more difficulties in authentication. Classical verification methods applied to 2-D signature or hand gesture cannot solve this problem. In order to improve the performance of in-air Chinese signature verification, the classical Global Sequence Alignment（GSA） algorithm was improved, and the interpolation was applied to matching sequences. Different from classical GSA algorithm which uses matching score to measure similarity between sequences, two distance indexes, Euclidean distance and absolute value distance, were introduced to calculate the differences between sequences after interpolation. Experimental results show that both of the two improved GSA algorithms can improve the accuracy of authentication, the Equal Error Rate（EER） of them are decreased by 37.6% and 52. 6%respectively compared with the classical method.