An identity authentication device is stylus-shaped. A processor is disposed within the device. The stylus-shaped device includes a scanner-type device component for capturing within the processor memory a written signature generated by the stylus while the stylus is writing upon a surface. A fingerprint sensor is disposed within the grip of the stylus. The fingerprint sensor enables the capture of a digital signature of the writer at the same time that the written signature of the writer is captured. Once the identity of the writer has been authenticated by comparison against a reference print, the signature of the writer irrefutable. The device serves the same general purpose and can be used in lieu of a signature pad. The device is either attached to a surface or is portable and wireless.