2007 年 35 巻 4 号 p. 259-264
A new personal identification method has been investigated which promises to be a useful technique for protecting society against the recent increase in card counterfeiting crimes. The method uses micro-cracks created in a transparent material made of acrylic resin as an ID-writer by means of a highly focused, diodepumped second-harmonic 532-nm YAG laser with an 8-ns pulse length. Various ID patterns were produced by varying the shape, the arrangement, and the number of spots using the laser-induced crack-creation technique. Using visible laser speckle patterns obtained from the micro-cracking region, reading image analysis was successfully accomplished by using a template matching method in an ID-reader configuration. The results indicate the possibility of up to 6.4 million ID discriminations. This experimental result indicated that the false acceptance rate and false rejection rate were sufficiently small to make this method a viable personal identificatio method.