A keyboard-input information-security apparatus and method are provided. The apparatus includes an interrupt-descriptor table for storing a list of addresses of functions for handling interrupts, and storing an address of a secure input interrupt-service routine at a specific location in an address area for an operating-system input interrupt-service routine supported by an operating system; a secure input-device driver for changing keyboard-interrupt-vector information to invoke the address of the secure input interrupt-service routine when a keyboard interrupt is generated by a keyboard, and receiving and encoding data input via the keyboard based on the address of the secure input interrupt-service routine; and a secure input unit for delivering the encoded data from the secure input-device driver to an application program, thereby providing higher-level security than a conventional keyboard-security scheme, and particularly, effectively blocking a port-polling attack or an action trying to change a setting in a debug register.