A device to protect a reproduction of a disk, a method of protecting the
reproduction of the disk, and a recording medium for the method. The
device includes a key setting unit to generate a key to encode lead-in
region information of the disk desired to be reproduced and a key storing
unit to store the key. A key storing unit in the device stores the key
generated by the key setting unit, and a reproduction determining unit
determines whether to reproduce the disk using the key.