Methods and apparatuses generating a radio base station key in a cellular radio system

• US 9,232,390 B2
• Filed: 07/01/2008
• Issued: 01/05/2016
• Est. Priority Date: 12/11/2007
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Blom, Rolf, Lindstrom, Magnus, Norrman, Karl
• Primary Examiner(s): Holder, Bradley
• Assistant Examiner(s): Baum, Ronald
• Application Number:
  US12/746,879
• Publication Number:
  US 20100267363A1
• Time in Patent Office: 2,744 Days
• Field of Search: 380/273
• US Class Current: 1/1
• CPC Class Codes: H04J 11/0069 Cell search, i.e. determining cell identity [cell-ID] design of multiplexing codes H04J13/00; processing access restriction or access information H04W48/16; discovery of network devices for network data management H04W8/005; sounding signals for channel estimation H04L25/0226; structure of reference signals in multicarrier modulation systems H04L27/2613; frame, time or carrier synchronisation in multicarrier modulation systems H04L27/2655
• CPC Class Codes: H04L 2463/061 applying further key derivation, e.g. deriving traffic keys from a pair-wise master key cryptographic mechanisms or cryptographic arrangements for generation of secret information including derivation or calculation of cryptographic keys or passwords H04L9/0861
• CPC Class Codes: H04L 9/0656 Pseudorandom key sequence combined element-for-element with data sequence, e.g. one-time-pad [OTP] or Vernam's cipher
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]
• CPC Class Codes: H04W 12/0431 Key distribution or pre-distribution; Key agreement
• CPC Class Codes: H04W 12/71 Hardware identity
• CPC Class Codes: H04W 12/73 Access point logical identity
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

In a method and a system for providing secure communication in a cellular radio system radio base station key is generated by determining a set of data bits known to both the UE and the radio base station, and creating the radio base station key in response to the determined set of data.

Claims

1. A method of creating a derived radio base station key in a source radio base station of an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access Network (E-UTRAN) cellular radio system in a connection with a User Equipment (UE) being connectable to the cellular radio system, said method comprising:

determining, by the source radio base station, that a set of data comprises an E-UTRAN physical cell identity specific to a particular target cell associated with a target radio base station of the cellular radio system, said physical cell identity known to both the UE and the source radio base station;

creating, by the source radio base station, the derived radio base station key based on the set of data and an existing cryptographic key used for communication between the UE and the source radio base station;

transmitting, by the source radio base station, the derived radio base station key to the target radio base station, said derived radio base station key being used during a handover of the user equipment between the radio base station and the target radio base station or during a reconnection of the user equipment to the cellular radio system.

2. The method according to claim 1, further comprising using additional input parameters as input data when creating the derived radio base station key.

3. The method according to claim 1, further comprising creating the derived radio base station key using a Pseudo-Random Function.

4. A radio base station operative in an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access Network (E-UTRAN) cellular radio system, the radio base station being adapted to create a derived radio base station key, the radio base station comprising:

a transmitter circuit and a receiver circuit configured to communicate with a User Equipment (UE);

wherein the radio base station is configured to;

determine, by the radio base station, a public E-UTRAN physical cell identity specific to a particular target cell associated with a target radio base station of the cellular radio system, said physical cell identity known to both the User Equipment (UE) communicating with the cellular radio system via a secure communication associated with an existing cryptographic key and the radio base station of the cellular radio system; and

create, by the radio base station, the derived radio base station key based on the E-UTRAN physical cell identity and the existing key;

transmit, by the radio base station, the derived radio base station key to the target radio base station, said derived radio base station key being used during a handover of the user equipment between the radio base station and the target radio base station or during a reconnection of the user equipment to the cellular radio system.

5. The radio base station according to claim 4, wherein the radio base station is configured to use additional input parameters as input data when creating the derived radio base station key.

6. The radio base station according to claim 4, wherein the radio base station is configured to create the derived radio base station key using a Pseudo-Random Function.