The invention relates to a method of obtaining a copy protected optical
record carrier carrying information in different blocks, a method of
accessing such a copy protected optical record carrier and such an optical
record carrier itself. Access devices for optical carriers return
different results when retrieving blocks, which contain incorrect address
data in the corresponding subcode fields. A copy protection key will be
implemented during manufacture of an optical record carrier by modifying
the subcode address information of a predetermined pattern of blocks. It
is normally not possible to copy incorrect address data onto an optical
record carrier, since the address data will be newly generated during the
copy process. Therefore, such a key can be utilized to distinguish between
an original disc and a copied or non original disc. The key is preset
before manufacturing of the optical record carrier itself and can
therefore be used to encrypt the data stored on the optical record
carrier. Upon accessing of the data, first the key is extracted from the
optical record carrier and then the data can be decrypted utilizing this
key.