IP Library Granted Patent US 8,229,115
Granted Patent B2
US 8,229,115 · App. 12/503,291 · Granted Jul 24, 2012

Use of copyright text in key derivation function

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Quick Facts
Patent No.
US 8,229,115
App. No.
12/503,291
Granted
Jul 24, 2012
Kind
B2
Abstract

Consistent with embodiments of the present invention, systems and methods are disclosed for deriving a secure key. In some embodiments, a method for deriving a key may be provided comprising: generating a first input value; loading a first register with the first input value; generating a second input value; loading a second register with the second input value; updating the first register and the second register at the same time, where the step of updating comprises: applying a first update function to the current value of the second register to determine a third input value; applying an XOR function to the third input value and a fixed string to determine a fourth input value, wherein the fixed string contains a legal notice; incrementing an offset to the fixed string; storing the fourth input value in the first register; applying a second update function to the current values of the first register and the second register to determine a fifth input value; storing the fifth input value in the second register; repeating the step of updating the first register and the second register a predetermined number of times; and outputting the value of the second register as the key.

Claims (69)

1. A method for deriving a key comprising:

generating a first input value;

loading a first register with the first input value;

generating a second input value;

loading a second register with the second input value different from the first input value;

updating the first register and the second register at a same time, where the step of updating comprises:

applying a first update function to a current value of the second register to determine a third input value;

applying an XOR function to the third input value and a fixed string to determine a fourth input value, wherein the fixed string contains a legal notice;

incrementing an offset to the fixed string with a predetermined number of bytes after said XOR function is applied;

storing the fourth input value in the first register;

applying a second update function to the current values of the first register and the second register to determine a fifth input value;

storing the fifth input value in the second register;

repeating the step of updating the first register and the second register a predetermined number of times; and

outputting the value of the second register as the key.

2. The method of claim 1 , further comprising storing the key on a set-top box.

3. The method of claim 2 , further comprising decrypting digital transmissions with the key and displaying the digital transmissions.

4. The method of claim 1 , wherein the offset is incremented in 4-byte intervals.

5. The method of claim 1 , wherein the first update function is defined by a user.

6. The method of claim 1 , wherein the key is employed in securing a digital transmission.

7. The method of claim 6 , wherein the key is employed to decrypt the digital transmission and display the transmission in an analog format.

8. The method of claim 1 , wherein the key is used in a key ladder.

9. A system comprising:

a first value generator connected to a first register;

a second value generator connected to a second register;

a function defining a generator capable of defining and executing one or more update functions;

a user definable fixed string containing a legal notice; and

a processor programmed to perform the steps of:

generate a first value with the first value generator;

generate a second value, different from the first value with the second value generator;

store the first value in the first register;

store the second value in the second register;

updating the first register and the second register at a same time, where the step of updating comprises:

applying a first update function to a current value of the second register to determine a third input value;

applying an XOR function to the third input value and the fixed string to determine a fourth input value;

increment an offset of the fixed string with a predetermined number of bytes after said XOR function is applied;

storing the fourth input value in the first register;

applying a second update function to the current values of the first register and the second register to determine a fifth input value;

storing the fifth input value in the second register;

execute the update functions on the values stored in the first and second registers such that the fixed string, the first value, and the second value are incorporated into an encryption key after repeating the step of updating the first register and the second register a predetermined number of times.

10. The system of claim 9 , further comprising an encryption device capable of employing the encryption key to encrypt digital communications.

11. The system of claim 10 , further comprising:

a plurality of set-top boxes each requiring a unique encryption key, wherein the plurality of set-top boxes are each in communication with the processor.

12. The system of claim 11 , wherein each of the plurality of set-top boxes has the encryption key stored in memory.

13. The system of claim 11 , wherein each of the plurality of set-top boxes accesses the encryption key from a remote location.

14. The system of claim 11 , wherein one or more of the plurality of set-top boxes employ the encryption key to decrypt digital transmissions and display the digital transmissions in an analog format.

15. A non-transitory computer-readable medium which stores a set of instructions which when executed performs a method for creating a secure key, the method executed by the set of instructions comprising:

generating a first input value;

loading a first register with the first input value;

generating a second input value;

loading a second register with the second input value different from the first input value;

updating the first register and the second register at a same time, where the step of updating comprises:

applying a first update function to a current value of the second register to determine a third input value;

applying an XOR function to the third input value and a fixed string to determine a fourth input value, wherein the fixed string contains a legal notice;

incrementing an offset to the fixed string with a predetermined number of bytes after said XOR function is applied;

storing the fourth input value in the first register;

applying a second update function to the current values of the first register and the second register to determine a fifth input value;

storing the fifth input value in the second register;

repeating the step of updating the first register and the second register a predetermined number of times; and

outputting the value of the second register as the key.

16. The non-transitory computer readable-medium of claim 15 , further comprising:

encrypting a communication with the secure key; and

transmitting the communication over a network.

17. The non-transitory computer readable-medium of claim 16 , further comprising:

associating the secure key with a unique device on the network.

18. The non-transitory computer readable-medium of claim 15 , further comprising:

storing the secure key on a secured microchip.

19. The non-transitory computer readable-medium of claim 18 , wherein the secured microchip is associated with a set-top box.

20. The non-transitory computer readable-medium of claim 19 , further comprising:

decrypting secure audio/video communications received at the set-top box.

Assignments (2)
CORRECTIVE ASSIGNMENT TO CORRECT THE PATENT 7523479 NEEDS TO BE INCLUDED, WAS ACCIDENTALLY MISSED WHEN RECORDING ASSIGNMENT PREVIOUSLY RECORDED ON REEL 049603 FRAME 0001. ASSIGNOR(S) HEREBY CONFIRMS THE NEED TO INCLUDE PATENT 7523479 IN THE ASSIGNMENT. WAS ACCIDENTALLY MISSED ON LAST RECORDING. Recorded Jun 9, 2021
From: CISCO TECHNOLOGY, INC.
To: TECH 5 SAS
Reel/Frame 058043/0001 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 20, 2020
From: THOMSON LICENSING S.A.S.
To: MAGNOLIA LICENSING LLC
Reel/Frame 053570/0237 →