The document proposes a 3D finger geometry authentication system as an improvement over existing hand geometry authentication methods. It captures 3D information using a low-cost depth sensor to limit constraints on hand placement. It extracts 3D geometry points from the finger and uses those as features for authentication, achieving similar accuracy to other methods but with greater convenience. It segments the finger, finds boundary points, enlarges the image, and extracts geometry points along circles projected inward from the boundary to generate the feature vector for matching. Preliminary results found the proposed system comparable to state-of-the-art hand geometry recognition.