Watermarking system that executes received watermarking instructions to embed a watermark
View Patent ↗A method of managing keys is provided. According to one exemplary method, digital content data encrypted with a first encrypting key is decrypted using a first decrypting key, and re-encrypted using a second encrypting key. A second decrypting key is encrypted using a third encrypting key to produce an encrypted second decrypting key. In some embodiments, an encrypted first decrypting key that was encrypted using a fourth encrypting key is received, and the encrypted first decrypting key is decrypted using a fourth decrypting key to reproduce the first decrypting key. An application for use on a computer system is also provided.
1. A non-transitory computer readable medium encoded with a program for watermarking digital content, the program comprising instructions for performing the steps of:
receiving digital content at a first device, the digital content including a first watermark;
receiving usage conditions for the digital content and encrypted watermarking instructions at the first device;
using a first decrypting key to decrypt the encrypted watermarking instructions so as to produce decrypted watermarking instructions; and
executing the watermarking instructions on the first device so as to embed a second watermark in the digital content, the second watermark including the usage conditions for the digital content,
wherein the program further comprises instructions for performing, on the first device, the steps of:
reading the second watermark that is embedded in the digital content in order to determine the usage conditions for the digital content;
if permitted by the usage conditions, copying the digital content; and
modifying the second watermark that is embedded in the digital content so as to update the usage conditions in the second watermark.
2. The computer readable medium as defined in claim 1 ,
wherein the step of receiving the digital content comprises the sub-steps of:
receiving encrypted digital content; and
using a decrypting key to decrypt the encrypted digital content so as to produce decrypted digital content, and
the executing step comprises embedding the second watermark in the decrypted digital content.
3. The computer readable medium as defined in claim 2 , wherein the program further comprises instructions for performing the step of:
after the executing step, re-encrypting the decrypted digital content using a symmetric key.
4. The computer readable medium as defined in claim 1 , wherein the second watermark comprises information for identifying the first device.
5. The computer readable medium as defined in claim 1 ,
wherein the step of receiving the encrypted watermarking instructions comprises receiving the encrypted watermarking instructions from a first computer, and
the step of using the first decrypting key comprises the sub-steps of:
receiving an encrypted first decrypting key from a second computer, which is different than the first computer; and
using a private key to decrypt the encrypted first decrypting key so as to produce the first decrypting key.
6. The computer readable medium as defined in claim 5 ,
wherein the step of receiving the encrypted watermarking instructions further comprises sending the encrypted watermarking instructions to the second computer, and receiving revised encrypted watermarking instructions from the second computer, and
the step of using the first decrypting key further comprises using the first decrypting key to decrypt the revised encrypted watermarking instructions so as to produce decrypted watermarking instructions.
7. The computer readable medium as defined in claim 1 ,
wherein the step of receiving the usage conditions comprises receiving watermarking parameters for the digital content, the watermarking parameters including the usage conditions for the digital content and identifying information, and
the second watermark that is embedded in the digital content includes all of the watermarking parameters.
8. The computer readable medium as defined in claim 1 , wherein the second watermark comprises a Transaction ID that uniquely identifies a transaction in which the digital content was purchased or licensed.
9. A method of watermarking digital content, the method comprising the steps of:
receiving digital content at a first device, the digital content including a first watermark;
receiving usage conditions for the digital content and encrypted watermarking instructions at the first device;
using a first decrypting key to decrypt the encrypted watermarking instructions so as to produce decrypted watermarking instructions;
executing the watermarking instructions on the first device so as to embed a second watermark in the digital content, the second watermark including the usage conditions for the digital content; and
after the executing step, performing the steps of:
reading the second watermark that is embedded in the digital content in order to determine the usage conditions for the digital content;
if permitted by the usage conditions, copying the digital content; and
modifying the second watermark that is embedded in the digital content so as to update the usage conditions in the second watermark.
10. The method as defined in claim 9 , wherein the second watermark comprises information for identifying the first device.
11. The method as defined in claim 9 , further comprising the step of embedding the first watermark by a content proprietor to identify the content proprietor.
12. An apparatus comprising:
a receiver for receiving digital content, usage conditions for the digital content, and encrypted watermarking instructions, the digital content including a first watermark;
a decrypter for using a first decrypting key to decrypt the encrypted watermarking instructions so as to produce decrypted watermarking instructions;
a watermarker for executing the watermarking instructions so as to embed a second watermark in the digital content, the second watermark including the usage conditions for the digital content; and
a copier for reading the second watermark that is embedded in the digital content in order to determine the usage conditions for the digital content, and copying the digital content if permitted by the usage conditions,
wherein if the copier copies the digital content, the watermarker modifies the second watermark that is embedded in the digital content so as to update the usage conditions in the second watermark.
13. The apparatus as defined in claim 12 ,
wherein receiver receives encrypted digital content,
the decrypter uses a decrypting key to decrypt the encrypted digital content so as to produce decrypted digital content, and
the watermarker embeds the second watermark in the decrypted digital content.
14. The apparatus as defined in claim 12 , wherein the second watermark comprises information for identifying the first device.
15. The apparatus as defined in claim 12 ,
wherein the receiver receives the encrypted watermarking instructions from a first computer, and receives an encrypted first decrypting key from a second computer, which is different than the first computer, and
the decrypter uses a private key to decrypt the encrypted first decrypting key so as to produce the first decrypting key.
16. The apparatus as defined in claim 15 , further comprising:
a transmitter for sending the encrypted watermarking instructions to the second computer,
wherein the receiver receives revised encrypted watermarking instructions from the second computer, and
the decrypter uses the first decrypting key to decrypt the revised encrypted watermarking instructions so as to produce decrypted watermarking instructions.