Method, medium, and apparatus, for determining whether a medium is copy protected

A method, medium, and apparatus for determining whether an optical disc is copy protected. The method includes measuring the level of radio frequency (RF) sum signals read from an optical disc, and establishing a gain of the RF sum signal; checking RF sum signals from an area of the optical disc in which no data is written; establishing a predetermined threshold level of the RF sum signals by using the RF sum signals read from a data recording area of the optical disc; comparing the level of the RF sum signals measured from the area in which no data is written with the sum of the level of the RF sum signals measured from the data recording area and the threshold level, and according to the comparison result, measuring the size of the area in which no data is written to determine whether the optical disc is a copy protected disc.