Method for establishing a connection between a terminal and an operating mobile radio network, mobile radio network and terminal used in such a method

• US 20040185829A1
• Filed: 11/22/2002
• Published: 09/23/2004
• Est. Priority Date: 05/22/2000
• Status: Active Grant

• Current Assignee: IP Edge LLC
• Original Assignee: Siemens AG
• Inventors: Vinck, Bart
• Granted Patent: US 7,620,183 B2
• Time in Patent Office: Days
• US Class Current: 455/410
• CPC Class Codes: H04W 12/03 Protecting confidentiality, e.g. by encryption
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 12/122 Counter-measures against attacks; Protection against rogue devices
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

According to the inventive method, a message is transmitted from an operating mobile radio network (NW2) to a terminal (MS1a) that identifies coding techniques (UEA-NW) supported by the operating mobile radio network in order to establish a connection between the terminal (MS1a) that supports a number (UEA-MS) of coding techniques and the operating mobile radio network (NW2). The terminal selects, if available, a coding technique (UEA) that is supported by the terminal and the operating mobile radio network (NW2), and the connection is operated using the coding technique selected by the terminal. If no coding technique is available that is supported by the terminal and the operating mobile radio network, the connection is operated uncoded only upon prior authorization.

Claims

1. A method for setting up a connection between a terminal (MS1a) which supports a set (UEA-MS) of encryption techniques, and a serving mobile radio network (NW2), with the following steps:

a) transmitting of a message from the serving mobile radio network (NW2) to the terminal (MS1a), which designates the encryption techniques (UEA-NW) supported by the serving mobile radio network (NW2);

b) if provided, selecting an encryption technique (UEA) which is supported by the terminal and by the serving mobile radio network, by the terminal (MS1a);

c) operating the connection by using the encryption technique selected by the terminal;

or

b′

) if no encryption technique supported by the terminal and by the serving mobile radio network is provided, unencrypted operating of the connection only after authorization.

2. The method as claimed in claim 1, characterized in that the message in step a) is transmitted with integrity protection.

3. The method as claimed in claim 1 or 2, characterized in that the terminal (MS1a) reports integrity protection techniques (UIA-MS) supported by it to the serving mobile radio network (NW2) and the serving mobile radio network (NW2) selects one among the integrity protection techniques (UIA-NW;

UIA-MS) supported by itself and by the terminal (MS1a) and transmits a message about the selected integrity protection technique (UIA) to the terminal (MS1a).

4. The method as claimed in claim 3, characterized in that the message in step a) contains the information about the integrity protection technique (UIA) selected by the serving mobile radio network (NW2).

5. The method as claimed in one of the preceding claims, characterized in that the serving mobile radio network (NW2) reports integrity protection techniques (UIA-NW) supported by it to the terminal (MS1a) and the terminal (MS1a) selects one (UIA′

) among the integrity protection techniques supported by itself and the serving mobile radio network (NW2), the connection being operated under the integrity protection technique selected by the terminal.

6. The method as claimed in claim 5, characterized in that the message in step a) contains the report of the integrity protection techniques (UIA-NW) supported by the serving mobile radio network (NW2).

7. The method as claimed in one of the preceding claims, characterized in that it also comprises the following step:

d) transmitting an encryption administration information item (AMF) from the home network (NW1) to the terminal (MS1a), which tells the terminal (MS1a) whether unencrypted connections to the serving mobile radio network (NW2) are necessary, where in step c), the connection is operated without encryption if the encryption administration information item (AMF) specifies that an unencrypted connection is necessary.

8. The method as claimed in claim 7, characterized in that in the case where the encryption administration information item (AMF) specifies that an unencrypted connection is necessary, the truth of this statement is checked at the terminal (MS1a).

9. The method as claimed in claim 7 or 8, characterized in that in the case where the encryption administration information item (AMF) specifies that an unencrypted connection is necessary, the user of the terminal (MS1a) is given the choice whether the connection is to be set up unencrypted or the connection attempt is to be aborted.

10. The method as claimed in claim 7 or 8, characterized in that in the case where the encryption administration information item (AMF) specifies that an unencrypted connection is necessary, the connection is set up unencrypted.

11. The method as claimed in claim 10, characterized in that a display of the terminal is operated in order to inform the user that the connection is unencrypted.

12. The method as claimed in one of claims 7 to 11, characterized that in step d), the encryption administration information item (AMF) is transmitted to the terminal (MS1a) via the serving network (NW2) and under integrity protection.

13. The method as claimed in one of claims 7 to 12, characterized in that in step d), the encryption administration information item (AMF) is transmitted to the terminal (MS1a) via the serving network (NW2) and on an authenticated signaling channel.

14. A terminal, particularly for carrying out a method as claimed in one of the preceding claims, characterized in that it has a control unit for selecting an encryption technique (UEA) which is supported by the terminal (MS1a) and by the serving mobile radio network (NW2).

15. The terminal as claimed in claim 14, characterized in that the control unit is also able to select an integrity protection technique which is supported by the terminal (MS1a) and by the serving mobile radio network (NW2).

16. The terminal as claimed in claim 14 or 15, characterized in that the control unit allows an unencrypted connection between the terminal (MS1a) and the serving mobile radio network (NW2) when an encryption administration information item (AMF) specifies that the serving mobile radio network (NW2) does not support an encryption technique.

17. The terminal as claimed in one of claims 14 to 16, characterized in that it exhibits an encryption display which indicates to a user whether the serving mobile radio network (NW2) supports an encryption technique.

18. The terminal as claimed in claim 17, characterized in that it is set up for receiving the encryption administration information item (AMF) during the setting-up of a connection by the serving mobile radio network (NW2).

19. The terminal as claimed in claim 17 or 18, characterized in that the control unit can be switched by a user between at least two of the following operating modes:

a first operating mode in which a connection is set up with a serving mobile radio network which does not support encryption and an encryption indication is operated in order to inform a user that the connection is unencrypted;

a second operating mode in which the attempt to set up a connection is aborted if the serving mobile radio network does not support an encryption technique;

a third operating mode in which, if the serving mobile radio network does not support an encryption technique, the attempt to set up a connection is interrupted and a user input is requested which determines whether the attempt is to be aborted or to be continued.

20. A mobile radio network, particularly for carrying out a method as claimed in one of the preceding claims, characterized in that it is able to obey an instruction by a terminal (MS1a) which designates an encryption technique (UEA) to be used for a connection between the terminal (MS1a) and the mobile radio network (NW2).

21. The mobile radio network as claimed in claim 20, characterized in that it is also able to obey an instruction by the terminal (MS1a), which designates an integrity protection technique (UIA′

) to be used for a connection between the terminal (MS1a) and the mobile radio network (NW2).

22. The mobile radio network as claimed in one of claims 20 or 21, characterized in that it is able to forward a message that a connection is to be set up between it and the terminal (MS1a) to a home network (NW1) of the terminal (MS1a) which differs from the mobile radio network (NW2) and to forward an encryption administration information item (AMF) from the home network (NW1) to the terminal (MS1a), which contains information about the encryption techniques (UEA-NW) supported by the mobile radio network (NW2).