A method for preventing a key logger from hacking the keyboard data typed on keyboard through authorization of keyboard data according to the present invention involves transmitting a seed and hash counter, which were created according to a ready-to-input signal in an application program to be protected from hacking, to a device driver; creating a first key data on the basis of the seed and hash counter or a keyboard data created by a keyboard interrupt created from outside in the device driver; creating a second key data on the basis of the seed and hash counter when the application program receives the first key data or a keyboard event data equivalent to the keyboard data; comparing the keyboard event data with the second key data; and receiving the keyboard event data as the data typed on keyboard when the keyboard event data is not identical with the second key data according to the result of the comparison of the prior step.