METHOD, APPARATUS, AND SYSTEM FOR PROVIDING ENCRYPTION OR INTEGRITY PROTECTION IN A WIRELESS NETWORK

• US 20180062847A1
• Filed: 04/08/2016
• Published: 03/01/2018
• Est. Priority Date: 04/08/2015
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Mildh, Gunnar, Basilier, Henrik, Cagenius, Torbjrn, Nilsson, Gunnar, Rommer, Stefan, Norell, Lennart, Rune, Gran, Sander, Ann-Christine
• Granted Patent: US 10,454,686 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 9/0643 Hash functions, e.g. MD5, SHA, HMAC or f9 MAC
• CPC Class Codes: H04L 9/0838 Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these network architectures or network communication protocols for key exchange in a packet data network H04L63/061
• CPC Class Codes: H04L 9/0861 Generation of secret information including derivation or calculation of cryptographic keys or passwords
• CPC Class Codes: H04L 9/14 using a plurality of keys or algorithms
• CPC Class Codes: H04L 9/3239 involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic
• CPC Class Codes: H04W 12/10 Integrity
• CPC Class Codes: H04W 8/08 Mobility data transfer
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A core network node identifies a non-USIM based authentication procedure to be utilized by a wireless communication device, WCD, being served by the core network node. The node obtains a session key associated with the identified non-USIM based authentication procedure. The node converts the session key associated with the identified non-USIM based authentication procedure to i) a first key, K₁, for use by the WCD and a base station serving the WCD to derive an encryption or integrity protection key, K_enc/int, for enabling encryption or integrity protection of a communication between the WCD and the base station or ii) a second key, K₂, for use by the WCD and the core network node to derive the first key K₁. The node then send i) K₁ to the base station or ii) K₂ to another core network node that is configured to derive K₁ from K₂.

Claims

1. A method, in a core network node, for establishing encryption or integrity protection, the method comprising:

identifying a non-USIM based authentication procedure to be utilized by a wireless communication device, WCD, being served by the core network node;

obtaining a session key associated with the identified non-USIM based authentication procedure;

converting the session key associated with the identified non-USIM based authentication procedure to at least one of;

i) a first key, K₁, for use by the WCD and a base station serving the WCD to derive an encryption or integrity protection key, K_enc/int, for enabling encryption or integrity protection of a communication between the WCD and the base station and ii) a second key, K₂, for use by the WCD and the core network node to derive the first key K₁; and

performing at least one of;

i) sending K₁ to the base station and ii) sending K₂ to another core network node that is configured to derive K₁ from K₂,

wherein K₁ and K₂ each has a length that is at least one of the following;

i) equal to a length of an evolved packet system authentication and key agreement (EPS AKA) key, and ii) different than a length of the session key.

2. The method of claim 1, wherein the core network node is a mobility management entity, MME, node, wherein obtaining the session key comprises receiving the session key from an authentication server, wherein the session key is converted to K₁, and wherein K₁ is sent from the MME node to the base station serving the WCD.

3. The method of claim 2, wherein K₁ is the K_eNB key used in the EPS AKA procedure, and wherein converting the session key comprises mapping the session key to a K_eNB format.

4. The method of claim 3, wherein the session key is longer than a predefined key length of the K_eNB format, and wherein mapping the session key to the K_eNB format comprises extracting a portion of the session key to be K_eNB, wherein the extracted portion has the predefined key length.

5. The method of claim 3, wherein the session key is shorter than the predefined key length of the K_eNB format, and wherein mapping the session key to the K_eNB format comprises padding the session key with additional bits to be K_eNB, wherein the padded session key has the predefined key length.

6. The method of claim 2, wherein converting the session key to K₁ comprises inputting the session key into a key derivation function, KDF, to output the K₁, wherein the KDF is a keyed-hash-message-authentication-code function using a secure hash algorithm, HMAC-SHA.

7. The method of claim 1, wherein the core network node is an authentication server, wherein the session key is converted to K₂, and wherein K₂ is sent to a MME node.

8. The method of claim 7, wherein K₂ is an access security management entity key, K_ASME, used in a EPS AKA procedure, and wherein converting the session key comprises mapping the session key to a K_ASME format.

9. The method of claim 8, wherein the session key is longer than a predefined key length of the K_ASME format, and wherein mapping the session key to the K_ASME format comprises extracting a portion of the session key to be K_ASME, wherein the extracted portion has the predefined key length.

10. The method of claim 8, wherein the session key is shorter than the predefined key length of the K_ASME format, and wherein mapping the session key to the K_ASME format comprises padding the session key with additional bits to be K_ASME, wherein the padded session key has the predefined key length.

11. The method of claim 8, wherein converting the session key to K_ASME comprises inputting the session key into a key derivation function, KDF, to output the K_ASME, wherein the KDF is a keyed-hash-message-authentication-code function using a secure hash algorithm, HMAC-SHA.

12. The method of claim 1, further comprising:

obtaining key generation data that is associated with the identified non-USIM based authentication procedure and that is for use in deriving the session key; and

sending the key generation data to the WCD.

13. The method of claim 1, wherein identifying the non-USIM based authentication procedure comprises identifying, from among a plurality of network partitions, a network partition to which the WCD is attempting to connect, and determining that the network partition is associated with the non-USIM based authentication procedure.

14. The method of claim 1, wherein identifying the non-USIM based authentication procedure comprises determining that the core network node has received at least one of the following from the WCD:

i) a user identifier and password, wherein the user identifier does not have an international mobile subscriber identity, IMSI, format and a password, and ii) a certificate.

15. The method of claim 1, wherein identifying the non-USIM based authentication procedure comprises receiving an indication of authentication type from the WCD, the indication associated with a non-USIM authentication procedure.

16. The method of claim 1, wherein identifying the non-USIM based authentication procedure comprises receiving subscription information associated with the WCD and accessing a database which associates subscription information with authentication procedure.

17. The method of claim 1, wherein identifying the non-USIM based authentication procedure comprises determining, from a device type of the WCD, that the WCD is not a mobile broadband, MBB, device.

18. A method, in a wireless communication device, WCD, for establishing encryption or integrity protection with a base station serving the WCD, the method comprising:

sending, to a mobility management entity, MME, node, non-USIM based authentication data;

receiving, from the MME node, key generation data associated with the non-USIM based authentication data;

generating a non-USIM based session key using the key generation data;

converting the non-USIM based session key to an encryption or integrity protection key, K_enc/int, for use by the WCD and the base station in encrypting or integrity protecting any communication between the WCD and the base station; and

sending, to the base station, a communication that is encrypted or integrity protected using the encryption or integrity protection key converted from the session key,

wherein the encryption or integrity protection key K_enc/int has a length that is at least one of the following;

i) equal to a length of an evolved packet system authentication and key agreement (EPS AKA) key, and ii) different than a length of the session key.

19. The method of claim 18, wherein converting the session key to K_enc/int comprises:

converting the session key to a first key, K₁, for use by the WCD and the base station to derive K_enc/int; and

converting K₁ to K_enc/int by inputting K₁ and an algorithm distinguisher value into a key derivation function, KDF, wherein the KDF is a hash function, and wherein the algorithm distinguisher value distinguishes between whether the output of the KDF is being used to perform encryption or integrity protection, and distinguishes between whether the output of the KDF is being used for radio resource control, RRC, signaling or for user plane, UP, signaling.

20. The method of claim 19, wherein converting the session key to K₁ comprises converting the session key to a second key K₂, and converting K₂ to K₁ by inputting K2 into the KDF.

21. The method of claim 18, wherein the key generation data comprises an identification of a type of authentication procedure between i) the WCD and the MME node or ii) the WCD and an authentication server to which the MME node is connected.

22. The method of claim 18, wherein the non-USIM based authentication data comprises at least one of:

i) user identifier and password, wherein the user identifier does not have an IMSI format, and ii) a certificate.

23. The method of claim 18, further comprising sending at least one of:

i) a identifier of a network partition the WCD is attempting to access, ii) an identifier of an authentication procedure to be used for authenticating the WCD, iii) a device type of the WCD, and iv) subscription information associated with the WCD.

24-32. -32. (canceled)

33. A core network node, for establishing encryption or integrity protection, the core network node comprising:

a network interface configured to receive communication from a wireless communication device, WCD; and

a data processing system that is connected to the network interface and that comprises one or more processors configured to;

identify a non-USIM based authentication procedure to be utilized by a wireless communication device, WCD, being served by the core network node;

obtain a session key associated with the identified non-USIM based authentication procedure;

convert the session key associated with the identified non-USIM based authentication procedure to at least one of;

i) a first key, K₁, for use by the WCD and a base station serving the WCD to derive an encryption or integrity protection key, K_enc/int, for enabling encryption or integrity protection of a communication between the WCD and the base station and ii) a second key, K₂, for use by the WCD and the core network node to derive the first key K₁; and

perform at least one of;

i) sending K₁ to the base station sending K₂ to another core network node that is configured to derive K₁ from K₂,

wherein K₁ and K₂ each has a length that is at least one of the following;

i) equal to a length of an evolved packet system authentication and key agreement (EPS AKA) key, and ii) different than a length of the session key.

34. The core network node of claim 33, wherein the core network node is a mobility management entity, MME, node, wherein the one or more processors are configured to obtain the session key by receiving the session key from an authentication server, wherein the session key is converted to K₁, and wherein K₁ is sent from the MME node to the base station serving the WCD.

35. The core network node of claim 34, wherein K₁ is the K_eNB key used in the EPS AKA procedure, and wherein the one or more processors are configured to convert the session key by mapping the session key to a K_eNB format.

36. The core network node of claim 35, wherein the session key is longer than a predefined key length of the K_eNB format, and wherein the one or more processors are configured map the session key to the K_eNB format by extracting a portion of the session key to be K_eNB, wherein the extracted portion has the predefined key length.

37. The core network node of claim 35, wherein the session key is shorter than the predefined key length of the K_eNB format, and wherein the one or more processors are configured to map the session key to the K_eNB format by padding the session key with additional bits to be K_eNB, wherein the padded session key has the predefined key length.

38. The core network node of claim 35, wherein the one or more processors are configured convert the session key to K₁ by inputting the session key into a key derivation function, KDF, to output the K₁, wherein the KDF is a keyed-hash-message-authentication-code function using a secure hash algorithm, HMAC-SHA.

39. The core network node of claim 33, wherein the core network node is an authentication server, wherein the session key is converted to K₂, and wherein K₂ is sent to a MME node.

34-1. The core network node of claim 39, wherein K₂ is an access security management entity key, K_ASME, used in a EPS AKA procedure, and wherein the one or more processors are configured to map the session key by mapping the session key to a K_ASME format.

44. The core network node of claim 33, wherein the one or more processors are further configured to:

obtain key generation data that is associated with the identified non-USIM based authentication procedure and that is for use in deriving the session key; and

send the key generation data to the WCD.

45. The core network node of claim 33, wherein the one or more processors are configured to identify the non-USIM based authentication procedure by identifying, from among a plurality of network partitions, a network partition to which the WCD is attempting to connect, and determining that the network partition is associated with the non-USIM based authentication procedure.

46. The core network node of claim 33, wherein the one or more processors are configured to identify the non-USIM based authentication procedure comprises by determining that the core network node has received at least one of the following from the WCD:

i) a user identifier and password, wherein the user identifier does not have an international mobile subscriber identity, IMSI, format and a password, and ii) a certificate.

47. The core network node of claim 33, wherein the one or more processors are configured to identify the non-USIM based authentication procedure by receiving an indication of authentication type from the WCD, the indication associated with a non-USIM authentication procedure.

48. The core network node of claim 33, wherein the one or more processors are configured to identify the non-USIM based authentication procedure by receiving subscription information associated with the WCD and accessing a database which associates subscription information with authentication procedure.

49. The core network node of claim 33, wherein the one or more processors are configured to identify the non-USIM based authentication procedure by determining, from a device type of the WCD, that the WCD is not a mobile broadband, MBB, device.

41. The core network node of claim 40, wherein the session key is longer than a predefined key length of the K_ASME format, and wherein the one or more processors are configured to map the session key to the K_ASME format by extracting a portion of the session key to be K_ASME, wherein the extracted portion has the predefined key length.

42. The core network node of claim 40, wherein the session key is shorter than the predefined key length of the K_ASME format, and wherein the one or more processors are configured to map the session key to the K_ASME format by padding the session key with additional bits to be K_ASME, wherein the padded session key has the predefined key length.

43. The core network node of claim 40, wherein the one or more processors are configured to map the session key to K_ASME by inputting the session key into a key derivation function, KDF, to output the K_ASME, wherein the KDF is a keyed-hash-message-authentication-code function using a secure hash algorithm, HMAC-SHA.

50. A wireless communication device, WCD, for establishing encryption or integrity protection with a base station serving the WCD, the WCD comprising:

a transceiver system for receiving communication from a mobility management entity, MME, node; and

a data processing system connected to the transceiver system and having one or more processors configured to;

send, to a mobility management entity, MME, node, non-USIM based authentication data;

receive, from the MME node, key generation data associated with the non-USIM based authentication data;

generate a non-USIM based session key using the key generation data;

convert the non-USIM based session key to an encryption or integrity protection key, K_enc/int, for use by the WCD and the base station in encrypting or integrity protecting communication between the WCD and the base station; and

send, to the base station, communication that is encrypted or integrity protected using the encryption or integrity protection key converted from the session key,

wherein the encryption or integrity protection key K_enc/int has a length that is at least one of the following;

i) equal to a length of an evolved packet system authentication and key agreement (EPS AKA) key, and ii) different than a length of the session key.

51. The WCD of claim 50, wherein the one or more processors are configured to convert the session key to K_enc/int by:

converting the session key to a first key, K₁, for use by the WCD and the base station to derive K_enc/int; and

converting K₁ to K_enc/int by inputting K₁ and an algorithm distinguisher value into a key derivation function, KDF, wherein the KDF is a hash function, and wherein the algorithm distinguisher value distinguishes between whether the output of the KDF is being used to perform encryption or integrity protection, and distinguishes between whether the output of the KDF is being used for radio resource control, RRC, signaling or for user plane, UP, signaling.

52. The WCD of claim 51, wherein the one or more processors are configured to convert the session key to K₁ by converting the session key to a second key K₂, and converting K₂ to K₁ by inputting K2 into the KDF.

53. The WCD of claim 50, wherein the key generation data comprises an identification of a type of authentication procedure between i) the WCD and the MME node or ii) the WCD and an authentication server to which the MME node is connected.

54. The WCD of claim 50, wherein the non-USIM based authentication data comprises at least one of:

i) user identifier and password, wherein the user identifier does not have an IMSI format, and ii) a certificate.

55-64. -64. (canceled)