A finger vein authentication system; comprising; a light source unit configured to emit near-infrared light; an optical filter unit configured to allow only light with a specific wavelength in light incident from the light source unit to penetrate there through; a CCD camera unit configured to capture an image of an user's finger and then to convert the captured image into an electrical signal; a control unit configured to drive a level set curvature program; a memory unit configured to store the level set curvature program, the level set curvature program adapted to cause extracting a finger vein pattern from the image of the finger using a level set curvature; wherein the level set curvature program instructs the control unit to (a) remove noise from the image of the finger obtained from the CCD camera unit by employing Gaussian filtering (b) remove a peripheral part of the finger from the image of the finger from which the noise is removed to separate the image of only the finger portion from the entire image by using an edge detect function which uses a divergence of gradient; (c) extract the finger vein pattern from the image of only the finger portion using the level set curvature, (d) binarize the extracted finger vein pattern, and (e) thinning the binarized finger vein pattern, (f) performing a processing operation for judging whether the finger vein pattern in the finger image coincides with the user's finger vein pattern registered in advance, characterised in that extracting of the finger vein pattern from the image of only the finger portion using the level set curvature is performed by a first operation for obtaining a pixel intensity value for each of all the pixels forming the image of only the finger, a second operation for mutually connecting the pixels having the same pixel intensity value in all the pixels to create one or more level sets which are a closed curve, a third operation for defining one or more level sets as a set of level sets, a fourth operation for creating one or more lines connecting points of the one or more level sets at which a curvature is minimized and being a valley, wherein the curvature in is obtained by the following equation. w ̅ = w / ‖ w ‖ if ‖ w ‖ > 0 0 d if ‖ w ‖ = 0 κ ̅ = − div w ̅ wherein K represents the curvature and w represents a gradient vector of the set of level sets, and a fifth operation for recognizing one or more lines as the finger vein pattern and extracting the lines. (a) remove noise from the image of the finger obtained from the CCD camera unit by employing Gaussian filtering (b) remove a peripheral part of the finger from the image of the finger from which the noise is removed to separate the image of only the finger portion from the entire image by using an edge detect function which uses a divergence of gradient; (c) extract the finger vein pattern from the image of only the finger portion using the level set curvature, (d) binarize the extracted finger vein pattern, and (e) thinning the binarized finger vein pattern, (f) performing a processing operation for judging whether the finger vein pattern in the finger image coincides with the user's finger vein pattern registered in advance, a first operation for obtaining a pixel intensity value for each of all the pixels forming the image of only the finger, a second operation for mutually connecting the pixels having the same pixel intensity value in all the pixels to create one or more level sets which are a closed curve, a third operation for defining one or more level sets as a set of level sets, a fourth operation for creating one or more lines connecting points of the one or more level sets at which a curvature is minimized and being a valley, wherein the curvature in is obtained by the following equation. w ̅ = w / ‖ w ‖ if ‖ w ‖ > 0 0 d if ‖ w ‖ = 0 κ ̅ = − div w ̅ wherein K represents the curvature and w represents a gradient vector of the set of level sets, and a fifth operation for recognizing one or more lines as the finger vein pattern and extracting the lines.