| 摘要 |
FIELD: data carriers, possible use for storing digital product. ^ SUBSTANCE: data carrier contains access information, ensuring provision of access to digital product, and additional channel, stored wherein is rewritable information of additional channel, used for encryption, decryption or checking of access information. additional channel on data carrier is stored practically in the same physical location as the access information, preventing, obstructing or impeding unsanctioned interference with access information. Also disclosed are recording and reading devices, which contains first means for recording/reading digital product and second recording/reading device for recording/reading access information. ^ EFFECT: prevented hacking of protection by means of repeated reproduction. ^ 4 cl, 4 dwg |
