A recording apparatus for modulating a master key used for encrypting main data in a pit-width direction by changing a light amount of a laser beam to then record it on an optical recording medium and records the main data encrypted by using the master key with correcting the main data so as to have a certain pit width and a pit length so that a jitter resulting in intersymbol interference of adjacent pits should be reduced. A reproducing apparatus for reproducing the recorded optical recording medium, and to thereby prevent an optical recording medium from being duplicated by an illegal copy.