1. A vein pattern management system for registering and authenticating a vein pattern acquired by radiating light to a portion of a living body, comprising: an imaging unit for capturing an image of a body surface of the portion of the living body with near-infrared light and generating near-infrared light imaging data; a vein pattern extraction unit for extracting a vein pattern from the near-infrared light imaging data by applying a differential filter, which outputs a large value for a pixel having a large difference between the pixel and its surrounding pixel, to a plurality of pixels constituting the near-infrared light imaging data; a pseudo-vein pattern determination unit for determining presence of a pseudo-vein pattern intentionally formed on a part of the captured body surface based on the extracted vein pattern; a vein pattern registration unit for registering the near-infrared light vein pattern based on a determination result from the determination unit to generate a registered vein pattern; and a vein pattern authentication unit for comparing a newly generated near-infrared light vein pattern with the registered vein pattern based on the determination result from the pseudo-vein pattern determination unit and authenticating the newly generated near-infrared vein pattern, wherein the vein pattern extraction unit calculates a distribution of output values based on acquired output values of the differential filter, and the pseudo-vein pattern determination unit determines the presence of the pseudo-vein pattern based on the distribution of the output values.