A reproducing apparatus for reproducing data from a record medium having a
program area and a management area, the program area being used for
recording a plurality of files, the management area being used for
managing forging prohibition information against a particular file
recorded in the program area is disclosed, the apparatus comprising a
calculating means for calculating the forging prohibition information
managed in the management area of the record medium whenever a file
recorded in the recorde medium is reproduced, a comparing means for
comparing a value calculated by the calculating means corresponding to a
former reproduction command with a value calculated by the calculating
means corresponding to a current reproduction command, and a controlling
means for permitting the file corresponding to the current reproduction
command to be reproduced when the value calculated corresponding to the
former reproduction command is the same as the value calculated
corresponding to the current reproduction command as the result of the
comparing means.