Method and apparatus for providing broadcast channel encryption to enhance cellular network security

1. A method for encrypting a broadcast message of a base station, the method comprising:

selecting, by a processor, an encryption key for the broadcast message;

encrypting, by the processor, the broadcast message using the encryption key to create an encrypted broadcast message;

transmitting, by the processor, an identifier of the encryption key;

transmitting, by the processor, the encrypted broadcast message over a broadcast channel;

detecting, by the processor, a communication impairment at the base station;

selecting, by the processor, a new encryption key; and

transmitting, by the processor, a new broadcast message that is encrypted with the new encryption key on the broadcast channel.

2. The method of claim 1 , wherein the processor comprises a processor of the base station.

3. The method of claim 2 , wherein the base station comprises one of: a NodeB or an eNodeB.

4. The method of claim 1 , wherein the identifier of the encryption key is transmitted unencrypted.

5. The method of claim 1 , wherein the identifier of the encryption key is transmitted over the broadcast channel.

6. The method of claim 1 , wherein the broadcast channel comprises a long term evolution broadcast channel.

7. The method of claim 1 , wherein the broadcast message comprises a master information block.

8. The method of claim 1 , wherein the broadcast message comprises a system information block.

9. The method of claim 1 , wherein the broadcast channel comprises a plurality of orthogonal frequency division multiple access physical resource blocks.

10. A method for encrypting a broadcast message of a base station, the method comprising:

assigning, by a processor, a control channel to a resource block, wherein the broadcast message includes information identifying that the control channel has been assigned to the resource block;

selecting, by the processor, an encryption key for the broadcast message;

encrypting, by the processor, the broadcast message using the encryption key to create an encrypted broadcast message;

transmitting, by the processor, an identifier of the encryption key;

transmitting, by the processor, the encrypted broadcast message over a broadcast channel;

detecting, by the processor, a physical layer attack on the base station;

reassigning, by the processor, the control channel to a different resource block; and

transmitting, by the processor, information identifying that the control channel has been assigned to the different resource block in a new broadcast message.

11. The method of claim 1 , wherein the encryption key comprises a spreading sequence.

12. The method of claim 11 , wherein the encrypting the broadcast message using the encryption key to create an encrypted broadcast message comprises spreading the broadcast message over a frequency band using the encryption key.

13. A computer-readable storage device storing instructions which, when executed by a processor, cause the processor to perform operations for encrypting a broadcast message of a base station, the operations comprising:

selecting an encryption key for the broadcast message;

encrypting the broadcast message using the encryption key to create an encrypted broadcast message;

transmitting an identifier of the encryption key; and

transmitting the encrypted broadcast message over a broadcast channel detecting a communication impairment at the base station;

selecting a new encryption key; and

transmitting a new broadcast message that is encrypted with the new encryption key on the broadcast channel.

14. The method of claim 10 , wherein the identifier of the encryption key is transmitted over the broadcast channel.

15. The method of claim 10 , wherein the broadcast message comprises a master information block.

16. The method of claim 10 , wherein the broadcast message comprises a system information block.

17. The method of claim 10 , wherein the broadcast channel comprises a plurality of orthogonal frequency division multiple access physical resource blocks.

18. The method of claim 10 , wherein the encryption key comprises a spreading sequence.

19. The method of claim 18 , wherein the encrypting the broadcast message using the encryption key to create an encrypted broadcast message comprises spreading the broadcast message over a frequency band using the encryption key.