User equipment authentication preventing sequence number leakage

1. An apparatus comprising:

at least one processor;

at least one memory including computer program code;

the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus at least to:

obtain a permanent identifier and an authentication sequence value that are unique to the apparatus;

conceal the permanent identifier and the authentication sequence value; and

send the concealed permanent identifier and the authentication sequence value in a registration message to a communication network.

2. The apparatus of claim 1 , wherein the at least one memory and the computer program code being configured to, with the at least one processor, further cause the apparatus to:

combine the permanent identifier and the authentication sequence value prior to concealment.

3. The apparatus of claim 1 , wherein the at least one memory and the computer program code being configured to, with the at least one processor, further cause the apparatus to:

in response to receipt of an authentication request message from the communication network, send a response message to the communication network containing a failure cause indication without a re-synchronization token.

4. The apparatus of claim 1 , wherein the at least one memory and the computer program code being configured to, with the at least one processor, further cause the apparatus to:

in response to receipt of an authentication request message from the communication network, send a response message to the communication network containing a failure cause indication without a re-synchronization token, wherein the failure cause indication indicates that the authentication sequence value had been sent earlier.

5. The apparatus of claim 1 , wherein the apparatus is part of user equipment configured for 5G authentication operations and the communication network is part of a 5G core network.

6. The apparatus of claim 5 , wherein the permanent identifier comprises a subscriber permanent identifier (SUPI) and the authentication sequence value comprises a sequence number (SQN) that are concatenated and encrypted as part of a subscriber concealed identifier (SUCI) and sent in the registration message.

7. The apparatus of claim 1 , wherein concealing the permanent identifier and the authentication sequence value comprises utilizing a combination of the permanent identifier and the authentication sequence value as an input to an encryption algorithm.

8. The apparatus of claim 7 , wherein the encryption algorithm comprises an elliptic curve integrated encryption scheme.

9. The apparatus of claim 7 , wherein the combination of the permanent identifier and the authentication sequence value comprises a concatenation of the permanent identifier and the authentication sequence value.

10. An apparatus comprising:

at least one processor;

at least one memory including computer program code;

the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus at least to:

obtain a permanent identifier and an authentication sequence value that are unique to the apparatus;

conceal the permanent identifier and the authentication sequence value;

send the concealed permanent identifier and the authentication sequence value in a registration message to a communication network; and

combine the permanent identifier and the authentication sequence value prior to concealment;

wherein combining the permanent identifier and the authentication sequence value prior to concealment further comprises concatenating the permanent identifier and the authentication sequence value to generate a single plain text block that is concealed and sent in the registration message.

11. A method comprising:

obtaining a permanent identifier and an authentication sequence value that are unique to user equipment;

concealing the permanent identifier and the authentication sequence value; and

sending the concealed permanent identifier and the authentication sequence value in a registration message from the user equipment to a communication network.

12. The method of claim 11 , further comprising combining the permanent identifier and the authentication sequence value prior to concealment.

13. The method of claim 11 , further comprising, in response to receipt of an authentication request message from the communication network, sending a response message to the communication network containing a failure cause indication without a re-synchronization token.

14. The method of claim 11 , further comprising, in response to receipt of an authentication request message from the communication network, sending a response message to the communication network containing a failure cause indication without a re-synchronization token, wherein the failure cause indication indicates that the authentication sequence value had been sent earlier.

15. The method of claim 11 , wherein the user equipment is configured for 5G authentication operations and the communication network is part of a 5G core network.

16. The method of claim 15 , wherein the permanent identifier comprises a subscriber permanent identifier (SUPI) and the authentication sequence value comprises a sequence number (SQN) that are concatenated and encrypted as part of a subscriber concealed identifier (SUCI) and sent in the registration message.

17. The method of claim 11 , wherein concealing the permanent identifier and the authentication sequence value comprises utilizing a combination of the permanent identifier and the authentication sequence value as an input to an encryption algorithm.

18. The method of claim 17 , wherein the encryption algorithm comprises an elliptic curve integrated encryption scheme.

19. The method of claim 17 , wherein the combination of the permanent identifier and the authentication sequence value comprises a concatenation of the permanent identifier and the authentication sequence value.

20. A method comprising:

obtaining a permanent identifier and an authentication sequence value that are unique to user equipment;

concealing the permanent identifier and the authentication sequence value;

sending the concealed permanent identifier and the authentication sequence value in a registration message from the user equipment to a communication network; and

combining the permanent identifier and the authentication sequence value prior to concealment;

wherein combining the permanent identifier and the authentication sequence value prior to concealment further comprises concatenating the permanent identifier and the authentication sequence value to generate a single plain text block that is concealed and sent in the registration message.

21. An article of manufacture comprising a non-transitory computer-readable storage medium having embodied therein executable program code that when executed by a processor causes the processor to perform the steps of:

obtaining a permanent identifier and an authentication sequence value that are unique to user equipment;

concealing the permanent identifier and the authentication sequence value; and

sending the concealed permanent identifier and the authentication sequence value in a registration message from the user equipment to a communication network.

22. The article of claim 21 , further comprising the step of combining the permanent identifier and the authentication sequence value prior to concealment.

23. The article of claim 21 , further comprising the step of, in response to receipt of an authentication request message from the communication network, sending a response message to the communication network containing a failure cause indication without a re-synchronization token.

24. The article of claim 21 , further comprising the step of, in response to receipt of an authentication request message from the communication network, sending a response message to the communication network containing a failure cause indication without a re-synchronization token, wherein the failure cause indication indicates that the authentication sequence value had been sent earlier.

25. The article of claim 21 , wherein concealing the permanent identifier and the authentication sequence value comprises utilizing a combination of the permanent identifier and the authentication sequence value as an input to an encryption algorithm.

26. The article of claim 21 , wherein the encryption algorithm comprises an elliptic curve integrated encryption scheme.

27. The article of claim 21 , wherein the combination of the permanent identifier and the authentication sequence value comprises a concatenation of the permanent identifier and the authentication sequence value.

28. An article of manufacture comprising a non-transitory computer-readable storage medium having embodied therein executable program code that when executed by a processor causes the processor to perform the steps of:

obtaining a permanent identifier and an authentication sequence value that are unique to user equipment;

concealing the permanent identifier and the authentication sequence value;

sending the concealed permanent identifier and the authentication sequence value in a registration message from the user equipment to a communication network; and

combining the permanent identifier and the authentication sequence value prior to concealment;

wherein combining the permanent identifier and the authentication sequence value prior to concealment further comprises concatenating the permanent identifier and the authentication sequence value to generate a single plain text block that is concealed and sent in the registration message.