Method for cryptographically verifiable identification of a physical unit in a public, wireless telecommunications network

• US 20040111616A1
• Filed: 08/01/2003
• Published: 06/10/2004
• Est. Priority Date: 05/26/2000
• Status: Active Grant

• Current Assignee: IPCom GmbH & Co KG
• Original Assignee: IPCom GmbH & Co KG
• Inventors: Adi, Wael
• Granted Patent: US 8,271,787 B2
• Time in Patent Office: Days
• US Class Current: 713/176
• CPC Class Codes: H04L 2209/26 Testing cryptographic entity, e.g. testing integrity of encryption key or encryption algorithm
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 63/126 the source of the received data
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/3271 using challenge-response
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 12/75 Temporary identity

Abstract

The invention creates a method for identification of a physical unit (M) in an open, wireless telecommunications network by means of a testing device (P), having the following steps: storing a secret identity (SIMEI) and an open identity (IMEI) in memory in the physical unit (M); generating a first parameter (CHv) in the testing device (P); sending an identity request (IR) with the first parameter (CHv) from the testing device (P) to the physical unit (M); generating an electronic signature (SIGt) by means of a first cryptographic function (F3) from the secret identity (SIMEI) and at least the first parameter (CHv) in the physical unit (M), and sending the generated electronic signature (SIGt) and the open identity (IMEI) to the testing device (P); generating the secret identity (SIMEI) from an open key (EMIGK) and from the sent open identity (IMEI) in the testing device (P); generating a corresponding electronic signature (SIGv) by means of the first cryptographic function (F3) from the generated first secret identity (SIMEI) in the testing device (P); and identifying the physical unit (M) by a comparison of the electronic signature (SIGt) sent and the corresponding electronic signature (SIGv) in the generated testing device (P).

Claims

1. A method for identification of a physical unit (M) in an open, wireless telecommunications network by means of a testing device (P), having the following steps:

a) storing a secret identity (SIMEI) and an open identity (IMEI) in memory in the physical unit (M);

b) generating a first parameter (CHv) in the testing device (P);

c) sending an identity request (IR) with the first parameter (CHv) from the testing device (P) to the physical unit (M);

d) generating an electronic signature (SIGt) by means of a first cryptographic function (F3) from the secret identity (SIMEI) and at least the first parameter (CHv) in the physical unit (M), and sending the generated electronic signature (SIGt) and the open identity (IMEI) to the testing device (P);

e) generating the secret identity (SIMEI) from an open key (EMIGK) and from the sent open identity (IMEI) in the testing device (P);

f) generating a corresponding electronic signature (SIGV) by means of the first cryptographic function (F3) from the generated first secret identity (SIMEI) in the testing device (P); and

g) identifying the physical unit (M) by a comparison of the electronic signature (SIGt) sent and the corresponding electronic signature (SIGV) in the generated testing device (P).

2. The method of claim 1, characterized in that the open key (EMIGK) is generated by a second cryptographic function (F2) from a first secret key (SMMK) and a second secret key (MIGK).

3. The method of one of claims 1 or 2, characterized in that the secret identity (SIMEI) is generated by a third cryptographic function (F1) from the open identity (IMEI) and the second secret key (MIGK).

4. The method of claim 3 in combination with claim 2, characterized in that the first secret key (SMMK) is stored in memory in the testing device (P), and the secret identity (SIMEI) is generated in the testing device (P) by means of the following steps:

generating the second secret key (MIGK) by means of the inverse (F2<sup>−

1</sup>) of the second cryptographic function (F2) from the first secret key (SMMK) and the open key (EMIGK); and

generating the secret identity (SIMEI) by means of the third cryptographic function (F1) from the open identity (IMEI) and the generated second secret key (MIGK).

5. The method of one of the foregoing claims, characterized in that the open key (EMIGK) is sent to the testing device over the internet.

6. The method of one of the foregoing claims, characterized by the following steps:

generating a second parameter (CHt) in the physical unit (M);

sending the second parameter (CHt) to the testing device (P); and

generating the electronic signature (SIGt) and the corresponding electronic signature (SIGv) from the secret identity (SIMEI) and the first and second parameters (CHv;

CHt).

7. The method of claim 6, characterized in that the first and second parameters (CHv;

CHt) are linked by means of an exclusive-OR function (+).

8. The method of claim 6, characterized in that the first and second parameters (CHv;

CHt) are multiplexed and then linked by means of an exclusive-OR function (+), with a feedback from the output of the first cryptographic function (F3) to the exclusive-OR (+).

9. The method of one of the foregoing claims, characterized in that the first and/or second parameters (CHv;

CHt) are provided in the form of random variables.

10. The method of one of the foregoing claims, characterized in that the telecommunications network is a mobile telephone system.

11. The method of one of the foregoing claims, characterized in that the first, second and third cryptographic functions (F1;

F2;

F3) are the identical function.

12. The method of claim 11 in combination with claim 9, characterized in that the identical function is a standard function.

13. The method of one of the foregoing claims, characterized in that steps d) and e) are performed on a smart card (MSC) in the testing device (P).