An information processing apparatus comprising: a processor configured to: extract a first region showing a feature of an object to be registered and having a predetermined size from an object surface image obtained by imaging a surface of the object; specify, from the object surface image, a second region to be compared with the first region and having a same size as the first region; derive a similarity between the first region and the second region; and characterized in that the processor is further configured to: extract a third region including the first region and having a larger size than the first region from the object surface image; specify, as a plurality of second regions, a plurality of regions obtained by shifting a region having a same size as the first region in the third region by one pixel at each time in a predetermined direction from a start end of the third region until the region moves to a terminal end of the third region; derive a plurality of similarities between the first region and the plurality of second regions; derive features indicative of a degree of distribution of the similarities obtained for a maximum similarity among the plurality of similarities; and register, as a registered image, the image of the first region in a case where the similarity between the first region and the second region is equal to or less than a threshold value and the features are equal to or more than a certain value; and wherein the processor is further configured to determine an authenticity of a target object by comparing an image of the target object with the registered image. extract a first region showing a feature of an object to be registered and having a predetermined size from an object surface image obtained by imaging a surface of the object; specify, from the object surface image, a second region to be compared with the first region and having a same size as the first region; derive a similarity between the first region and the second region; and characterized in that the processor is further configured to: extract a third region including the first region and having a larger size than the first region from the object surface image; specify, as a plurality of second regions, a plurality of regions obtained by shifting a region having a same size as the first region in the third region by one pixel at each time in a predetermined direction from a start end of the third region until the region moves to a terminal end of the third region; derive a plurality of similarities between the first region and the plurality of second regions; derive features indicative of a degree of distribution of the similarities obtained for a maximum similarity among the plurality of similarities; and register, as a registered image, the image of the first region in a case where the similarity between the first region and the second region is equal to or less than a threshold value and the features are equal to or more than a certain value; and wherein the processor is further configured to determine an authenticity of a target object by comparing an image of the target object with the registered image. extract a third region including the first region and having a larger size than the first region from the object surface image; specify, as a plurality of second regions, a plurality of regions obtained by shifting a region having a same size as the first region in the third region by one pixel at each time in a predetermined direction from a start end of the third region until the region moves to a terminal end of the third region; derive a plurality of similarities between the first region and the plurality of second regions; derive features indicative of a degree of distribution of the similarities obtained for a maximum similarity among the plurality of similarities; and register, as a registered image, the image of the first region in a case where the similarity between the first region and the second region is equal to or less than a threshold value and the features are equal to or more than a certain value; and wherein the processor is further configured to determine an authenticity of a target object by comparing an image of the target object with the registered image.