Authentication in a packet data network

• US 7,107,620 B2
• Filed: 01/08/2001
• Issued: 09/12/2006
• Est. Priority Date: 03/31/2000
• Status: Expired due to Term

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Haverinen, Henry, Honkanen, Jukka-Pekka, Ala-Laurila, Juha, Asokan, Nadarajah, Rinnemaa, Jyri, Ekberg, Jan-Erik, Takamäki, Timo, Vuonnala, Raimo, Flykt, Patrik, Honkanen, Seppo, Aalto, Petri, Kuikka, Antti, Mikkonen, Tommi
• Primary Examiner(s): Morse, Gregory
• Assistant Examiner(s): Simitoski, Michael J.
• Application Number:
  US09/756,346
• Publication Number:
  US 20020012433A1
• Time in Patent Office: 2,073 Days
• Field of Search: 713/153, 713/168, 709/223, 709/225, 709/229, 709/238, 380/270, 380/273, 455/432.1, 455/410, 455/411, 455/415, 455/428, 455/433, 726/29
• US Class Current: 726/29
• CPC Class Codes: H04L 63/0435 wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/0853 using an additional device, e.g. smartcard, SIM or a different communication terminal cryptographic mechanisms or cryptographic arrangements for entity authentication involving additional secure or trusted devices H04L9/3234
• CPC Class Codes: H04L 63/0869 for achieving mutual authentication cryptographic mechanisms or cryptographic arrangements for mutual authentication H04L9/3273
• CPC Class Codes: H04L 63/162 at the data link layer
• CPC Class Codes: H04W 12/0431 Key distribution or pre-distribution; Key agreement
• CPC Class Codes: H04W 12/06 Authentication

Abstract

Authentication method for authenticating a mobile node to a packet data network, in which a shared secret for both the mobile node and the packet data network is arranged by using a shared secret of the mobile node and a telecommunications network authentication center. In the method, the mobile node sends its subscriber identity to the packet data network together with a replay attack protector. The packet data network obtains authentication triplets, forms a session key using them, and sends back to the mobile node challenges and a cryptographic authenticator made by using the session key. The mobile node can then form the rest of the authentication triplets using the challenges and then form the session key. With the session key, the mobile node can check the validity of the cryptographic authenticator. If the authenticator is correct, the mobile node sends a cryptographic response formed using the session key to the packet data network for authenticating itself to the packet data network.

Claims

1. Authentication method for authenticating a mobile node to a packet data network, comprising the steps of:

providing the mobile node with a mobile node identity and a shared secret specific to the mobile node identity and usable by a telecommunications network;

providing the mobile node with a protection code;

sending the mobile node identity and the protection code from the mobile node to the packet data network;

providing the packet data network with authentication information usable by the telecommunications network, the authentication information comprising a challenge based on RAND codes of at least two authentication triplets of the telecommunications network, and a session secret corresponding to the mobile node identity and derivable using the challenge and the shared secret;

forming cryptographic information using at least the protection code and the session secret;

sending the challenge and the cryptographic information from the packet data network to the mobile node;

checking at the mobile node the validity of the cryptographic information using the challenge and the shared secret;

generating at the mobile node the session secret and a first response corresponding to the challenge, based on the shared secret;

sending the first response to the packet data network; and

checking the first response for authenticating the mobile node.

2. Method according to claim 1 further comprising the steps of:

providing the mobile node with a subscriber identity for the telecommunications network; and

forming from the subscriber identity a Network Access Identifier as the mobile node identity by the mobile node.

3. Method according to claim 1 further comprising the step of recognising the telecommunications network at the packet data network directly from the mobile node identity.

4. Method according to claim 1, further comprising the step of providing the packet data network with a shared session key based on the session secret.

5. Method according to claim 1, further comprising the step of providing a communications link between the packet data network and the mobile node for communicating the challenge between them, the communications link not being a link of the telecommunications network.

6. Method according to claim 1, further comprising the step of using a Subscriber Identity Module for the providing the mobile node with a mobile node identity and the generating of the session secret based on a shared secret specific for the mobile node identity.

7. Method according to claim 6, wherein the step of providing the mobile node with the mobile node identity and the shared secret specific for the mobile node identity further comprises the sub-steps of:

forming a local connection between the mobile node and a subscriber identity module; and

receiving from the subscriber identity module to the mobile node the mobile node identity and a session secret specific to the mobile node identity.

8. Method according to claim 1, further comprising the steps of:

obtaining a second response by the telecommunications network; and

using the second response in the checking the first response.

9. Method according to claim 1, further comprising the step of sending the challenge from the telecommunications network to the mobile node via the packet data network.

10. Method according to claim 1, wherein the protection code is based on time.

11. Method according to claim 1, further comprising the step of generating a shared session key for Internet Key Exchange, wherein the shared session key is based on the session secret and the challenge.

12. A network entity for acting as an interface between a packet data network and a telecommunications network having an access to an authentication server, the network entity comprising:

an input for receiving a mobile node identity and a protection code from the packet data network;

an output for providing the authentication server with the mobile node identity;

an Input for receiving a challenge and a session secret corresponding to the mobile node identity from the authentication server;

a first processor for forming cryptographic information using at least the protection code and the session secret;

an output for providing the packet data network with the challenge and the cryptographic information for further transmission to a mobile node;

an input for receiving a first response corresponding to the challenge, based on a shared secret spedflc to the subscriber identity and known by the mobile node and the telecommunications network, from the mobile node via the packet data network; and

a second processor for verifying the first response for authenticating the mobile node, and

wherein the network entity is configured to receive at least two challenges corresponding to the mobile node identity from the authentication server, to form the cryptographic information based on the at least two received challenges and to output the at least two received challenges and the cryptographic information for further transmission to the mobile node.

13. A network entity according to claim 12 further comprising:

an output for providing the mobile node with a subscriber identity (IMSI) for the telecommunications network; and

a processor for forming from the subscriber identity a Network Access Identifier (NAI) as the mobile node identity by the mobile node.

14. A network entity according to claim 12 further configured to generate a shared session key for Internet Key Exchange, wherein the shared session key is based on at least one session secret and at least one challenge.

15. The network entity of claim 12 wherein the network entity comprises a gateway.