Method and apparatus for DVD copy protection with selective data pattern insertion
View Patent ↗Method and apparatus for inhibiting unauthorized copying of data content of DVDs or CDs or other types of optical discs. DSV (digital sum value) data patterns are inserted into selected sectors of the data to be recorded on the optical disc. These selected data sectors are also those to which is applied the conventional CSS (content scrambling system) encryption conventionally used to copy protect DVD content. Only those sectors (e.g., one out of four) subject to the CSS encryption have the DSV data patterns inserted therein. This advantageously results in the CSS encryption effectively hiding these inserted DSV data patterns from the mastering DVD encoder used in producing DVDs. Effectively thereby the DSV data patterns “tunnel through” the mastering DVD encoder. The hidden DSV data patterns are only revealed when the CSS sectors are decrypted prior to the action of the writer used to copy the DVD/CD content. This results in those DSV data patterns being left in the clear at the writer so they are effective to result in an error-filled DVD data file which is not suitable for play back when recorded by the writer on another optical disc.
1. A method of copy protecting content data on a consumer CD or DVD optical disk suitable for playing on a typical player, the content data being organized in a plurality of sectors, comprising the acts of:
inserting predetermined data patterns into selected ones of the sectors, the data patterns including, when played back, repeated patterns of values;
applying content scrambling system (CSS) encryption to each of the selected sectors; and
providing the content data including the selected CSS encrypted sectors, the remaining sectors, and at least one key associated with CSS decryption of the selected sectors wherein the predetermined data patterns are each hidden by the CSS encryption;
writing the provided data to an optical disk master; and
making a plurality of consumer CD or DVD optical disks from the optical disk master, wherein on the consumer CD or DVD optical disks, the predetermined data patterns are each hidden by the CSS encryption and decrypted in the typical player upon play of the consumer CD or DVD; wherein the predetermined data patterns are Digital Sum Value (DSV) data patterns, there being a plurality of the DSV data patterns on each optical disk, each of the plurality of DSV data patterns being 2 to 20 bytes in length and there being 1,000 to 5,000 bytes of DSV data patterns for each 32 of the plurality of the sectors.
2. The method of claim 1 , wherein the DSV data patterns are such as to cause a digital sum value of a playback of the data to have an absolute value greater than a predetermined value.
3. The method of claim 1 , wherein the DSV data patterns are such as to cause a digital sum value of a playback of the data to have a rate of change greater than a predetermined value.
4. The method of claim 1 , wherein the DSV data patterns are such as to cause a digital sum value of a playback of the data to have a predetermined low frequency component.
5. The method of claim 1 , wherein the selected ones of the sectors are one out of each four sectors.
6. The method of claim 1 , further comprising the acts of:
inserting index files into the data; and
formatting the data.
7. The method of claim 1 , further comprising the acts of:
organizing the data into data frames;
scrambling the data frames;
determining error codes to the data; and
modulating the data.
8. A consumer CD or DVD optical disc suitable for playing on a typical player and carrying content data comprising:
a first plurality of sectors each including content data subjected to content scrambling system (CSS) encryption;
a second plurality of sectors each including content data not subjected to the CSS encryption; and
at least one key associated with CSS decryption of the first plurality of sectors;
wherein the first plurality of sectors also each include a predetermined data pattern subject to the CSS encryption which upon being CSS decrypted and played back includes a repeated pattern of values wherein the predetermined data patterns are each hidden by the CSS encryption, and none of the second plurality of sectors include such a predetermined data pattern; wherein the predetermined data patterns are decrypted in the typical player upon play of the consumer CD or DVD; wherein the predetermined data patterns are Digital Sum Value (DSV) data patterns, there being a plurality of the DSV data patterns on each optical disk, each of the plurality of DSV data patterns being 2 to 20 bytes in length and there being 1,000 to 5,000 bytes of DSV data patterns for each 32 of the plurality of the sectors.
9. The disc of claim 8 , wherein the DSV data patterns are such as to cause a digital sum value of the playback of the data to have an absolute value greater than a predetermined value.
10. The disc of claim 8 , wherein the DSV data patterns are such as to cause a digital sum value of the playback of the data to have a rate of change greater than a predetermined value.
11. The disc of claim 8 , wherein the DSV data patterns are such as to cause a digital sum value of the playback of the data to have a predetermined low frequency component.
12. The disc of claim 8 , wherein the first plurality of the sectors is one out of four of the sectors.
13. The disc of claim 8 , the data further comprising index files.
14. The disc of claim 8 , wherein:
the data is organized into data frames;
the data frames are scrambled; and the data further comprising error codes.