A digital work (102) and copyright management information (103) for the digital work are recorded on an information recording medium (101) by altering a shape, a position or a pattern (104, 105) of recording mark edges of the digital work. Alternatively, a decryption key for the right management information is recorded on an information recording medium on which the copyright management information has been recorded encrypted, by altering the recording mark edges of the copyright management information. Alternatively, a check code for the copyright management information is recorded on the information recording medium by altering the recording mark edges. The check code is checked when the copyright management information is read, thus detecting illegal use of the copyright management information.