Method and apparatus for augmenting authentication in a cryptographic system

1. A method for an augmented authentication unit, separate from a cryptographic system, to modify an authentication protocol of the cryptographic system comprising:

detecting, with communication hardware of the augmented authentication unit, a nonce to be used by the authentication protocol from a communication stream;

removing the nonce from the communication stream intercepted responsive to the detection;

encrypting, with processing hardware of the augmented authentication unit, the nonce into an encrypted nonce based on a shared secret formed by an authenticated key exchange; and

inserting the encrypted nonce back into the communication stream.

2. The method of claim 1 , wherein the nonce is an An value generated by a High-bandwidth Digital Content Protection (HDCP) function.

3. The method of claim 1 , wherein the communication stream is an Inter-Integrated Circuit (I 2 C) communication path.

4. The method of claim 1 , wherein the authenticated key exchange is to use signed Diffie-Hellman Key Exchange.

5. A method for an augmented authentication unit, separate from a cryptographic system, to modify an authentication protocol of the cryptographic system comprising:

detecting, with communication hardware of the augmented authentication unit, an encrypted nonce from a communication stream used by the authentication protocol;

removing the encrypted nonce from the communication stream responsive to the detection;

decrypting, with processing hardware of the augmented authentication unit, the encrypted nonce into an decrypted nonce based on a shared secret formed by an authenticated key exchange, wherein the decrypted nonce is to be used in the authentication protocol; and

inserting the decrypted nonce back into the communication stream.

6. The method of claim 5 , wherein the nonce is an An value generated by a High-bandwidth Digital Content Protection (HDCP) function.

7. The method of claim 5 , wherein the communication stream is an Inter-Integrated Circuit (I 2 C) communication path.

8. The method of claim 5 , wherein the authenticated key exchange is to use Diffie-Hellman Key Exchange.

9. A machine-readable storage medium having instructions stored thereon which, when executed by a machine, cause the machine to perform a method of for an augmented authentication unit, separate from a cryptographic system, to modify an authentication protocol of the cryptographic system comprising:

detecting a nonce to be used by the authentication protocol from a communication stream;

removing the nonce from the communication stream intercepted responsive to the detection;

encrypting the nonce into an encrypted nonce based on a shared secret formed by an authenticated key exchange; and

inserting the encrypted nonce back into the communication stream.

10. The machine-readable medium of claim 9 , wherein the nonce is an An value generated by a High-bandwidth Digital Content Protection (HDCP) function.

11. The machine-readable medium of claim 9 , wherein the communication stream is an Inter-Integrated Circuit (I 2 C) communication path.

12. The machine-readable medium of claim 9 , wherein the authenticated key exchange is to use Diffie-Hellman Key Exchange.

13. A machine-readable storage medium having instructions stored thereon which, when executed by a machine, cause the machine to perform a method of for an augmented authentication unit, separate from a cryptographic system, to modify an authentication protocol of the cryptographic system comprising:

detecting an encrypted nonce from a communication stream used by the authentication protocol;

removing the encrypted nonce from the communication stream responsive to the detection;

decrypting the encrypted nonce into an decrypted nonce based on a shared secret formed by an authenticated key exchange, wherein the decrypted nonce is to be used in the authentication protocol; and

inserting the decrypted nonce back into the communication stream.

14. The machine-readable medium of claim 13 , wherein the nonce is an An value generated by a High-bandwidth Digital Content Protection (HDCP) function.

15. The machine-readable medium of claim 13 , wherein the communication stream is an Inter-Integrated Circuit (I 2 C) communication path.

16. The machine-readable medium of claim 13 , wherein the authenticated key exchange is to use Diffie-Hellman Key Exchange.

17. An apparatus comprising:

a first unit to provide a nonce in a communication stream during an authentication exchange phase of a cryptographic system; and

a second unit coupled with the first unit:

to detect the nonce from the communication stream;

to remove the nonce from the communication stream responsive to the detection;

to encrypt the nonce into an encrypted nonce based on a shared secret formed by an authenticated key exchange; and

to insert the encrypted nonce back into the communication stream.

18. The apparatus of claim 17 , wherein the nonce is an An value generated by a High-bandwidth Digital Content Protection (HDCP) function.

19. The apparatus of claim 17 , wherein the communication stream is an Inter-Integrated Circuit (I 2 C) communication path.

20. The apparatus of claim 17 , wherein the first unit is a High-bandwidth Digital Content Protection (HDCP) transmitter.

21. The apparatus of claim 17 , wherein the authenticated key exchange is to use Diffie-Hellman Key Exchange.

22. An apparatus comprising:

a first unit:

to detect an encrypted nonce from a communication stream;

to remove the encrypted nonce from the communication stream responsive to the detection;

to decrypt the encrypted nonce into an decrypted nonce based on a shared secret formed by an authenticated key exchange; and

to insert the decrypted nonce back into the communication stream; and

a second unit coupled with the first unit to receive the decrypted nonce from the communication stream during an authentication exchange phase of a cryptographic system.

23. The apparatus of claim 22 , wherein the nonce is an An value generated by a High-bandwidth Digital Content Protection (HDCP) function.

24. The apparatus of claim 22 , wherein the communication stream is an Inter-Integrated Circuit (I 2 C) communication path.

25. The apparatus of claim 22 , wherein the second unit is an High-bandwidth Digital Content Protection (HDCP) receiver.

26. The apparatus of claim 22 , wherein the authenticated key exchange is to use Diffie-Hellman Key Exchange.

27. A system comprising:

a transmitter device including:

a first unit to provide a nonce in a communication stream during an authentication exchange phase of a cryptographic system; and

a second unit coupled with the first unit:

to detect the nonce from the communication stream;

to remove the nonce from the communication stream responsive to the detection of the nonce;

to encrypt the nonce into an encrypted nonce based on a shared secret formed by an authenticated key exchange; and

to insert the encrypted nonce back into the communication stream; and

at least one receiver device to receive data from the transmitter device, the at least one receiver device comprising:

a third unit:

to detect the encrypted nonce from the communication stream;

to remove the encrypted nonce from the communication stream responsive to the detection of the encrypted nonce;

to decrypt the encrypted nonce into an decrypted nonce based on the shared secret; and

to insert the decrypted nonce back into the communication stream;

and

a fourth unit coupled with the third unit to use the nonce from the communication stream during the authentication exchange phase.

28. The system of claim 27 , wherein the nonce is an An value generated by a High-bandwidth Digital Content Protection (HDCP) function.

29. The system of claim 27 , wherein the communication stream is an Inter-Integrated Circuit (I 2 C) communication path.

30. The system of claim 27 , wherein the authenticated key exchange is to use Diffie-Hellman Key Exchange between the second unit and the third unit.