Methods and apparatus to verify the identity of a cellular mobile phone

• US 5,457,737 A
• Filed: 12/28/1993
• Issued: 10/10/1995
• Est. Priority Date: 12/28/1993
• Status: Expired due to Fees

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Wen, Jack C.
• Primary Examiner(s): Chan, Wing F.
• Assistant Examiner(s): TROST IV, WILLIAM GEORGE
• Application Number:
  US08/174,569
• Time in Patent Office: 651 Days
• Field of Search: 380/21, 380/23, 379/62, 379/59, 379/63, 379/58, 455/33.1, 455/54.1
• US Class Current: 455/410
• CPC Class Codes: H04L 12/22 Arrangements for preventing the taking of data from a data transmission channel without authorisation means for verifying the identity or the authority of a user of a secure or secret communication system H04L9/32
• CPC Class Codes: H04L 63/083 using passwords cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226
• 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 63/1475 Passive attacks, e.g. eavesdropping or listening without modification of the traffic monitored
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 12/08 Access security
• CPC Class Codes: H04W 12/71 Hardware identity

Abstract

A wireless-based communications system is provided with a method and apparatus for automatic verification of the identity of a mobile phone user in order to eliminate cellular piracy. A first embodiment implements a memory-based verification and a second embodiment implements an algorithm-based verification to reduce memory space requirements. The call is allowed when verification passes and is disallowed when verification fails.

Claims

1. A method for a base station in a wireless-based communications system to automatically verify the identity of a mobile phone prior to connecting a requested wireless call, the method comprising the steps of:

(a) receiving a request by the mobile phone to the base station to connect a wireless call;

(b) transmitting in response to the request a unique interrogation address from the base station to the mobile phone;

(c) fetching from memory in the base station an expected code word, the expected code word residing at the location specified by the unique interrogation address;

(d) fetching from memory in the mobile phone a unique code word, the unique code word residing at the location specified by the unique interrogation address;

(e) transmitting the unique code word from the mobile phone to the base station;

(f) verifying that the expected code word fetched from the base station memory is the same as the unique code word received from the mobile phone;

(g) connecting the requested wireless call only when the code words are the same; and

(h) denying the requested wireless call when the code words are not the same.

2. The method of claim 1 comprising the additional step of

(i) changing the unique interrogation address prior to a subsequent verification whereby the unique code word fetched from the mobile phone memory and the expected code word fetched from the base station memory are different from prior verifications.

3. The method of claim 2 in which the interrogation address changing step is effected incrementally.

4. The method of claim 2 in which the interrogation address changing step is effected pseudo-randomly.

5. The method of claim 2 comprising the additional step of:

(j) informing the mobile phone that the requested wireless call has been denied.

6. The method of claim 5 comprising the additional steps of:

(k) counting the number of failed verifications within a preset time period; and

(l) alerting the service provider when the number of failed verifications within a preset time period is more than a preset amount.

7. In a wireless-based communications system having a base station and at least one mobile phone, apparatus for automatically verifying the identity of a mobile phone prior to connecting a requested wireless call comprising:

(a) means in the mobile phone to request the connection of a wireless call;

(b) means in the base station to generate and transmit a unique interrogation address in response to the mobile phone request;

(c) memory means in the base station for storing a set of expected unique code words reserved for each mobile phone in the wireless-based system;

(d) memory means in the mobile phone for storing a set of unique code words identical to the set reserved in the base station memory means for the particular mobile phone;

(e) means to provide to the base station the unique code word from the mobile phone memory means which corresponds to the unique interrogation address;

(f) means in the base station to compare the mobile phone code word with the expected code word from the base station memory means which corresponds to the unique interrogation address; and

(g) means for connecting the wireless call only when the mobile phone code word is the same as the base station expected code word and for denying the connection of the wireless call when the mobile phone code word and is not the same as the base station expected code word.

8. The wireless-based communications system of claim 7 further comprising:

(h) means for changing the unique interrogation address prior to a subsequent verification whereby the unique code word from the mobile phone memory means and the expected code word from the base station memory are changed from prior verifications.

9. The wireless-based communications system of claim 8 in which the address changing means is an incremental counter.

10. The wireless-based communications system of claim 8 in which the address changing means is a pseudo-random number generator.

11. The wireless-based communications system of claim 8 further comprising:

(i) means for informing the mobile phone that the requested wireless call has been denied.

12. The wireless-based communications system of claim 11 further comprising:

(j) means for counting the number of failed verifications within a preset time period; and

(k) means for alerting the service provider when the number of failed verifications within a preset time period is more than a preset amount.

13. In a wireless-based communications system comprising a plurality of mobile phones and a base station capable of communicating with each of the mobile phones, a system for verifying the identity of any of the mobile phones wherein:

(a) each of the mobile phones comprises;

(i) means to request the connection of a wireless call,

(ii) means to receive a unique interrogation address provided by the base station in response to the request,

(iii) memory means for storing a set of predetermined unique code words, and

(iv) means to provide to the base station a unique mobile phone code word from the memory means which corresponds to the unique interrogation address, and

(b) the base station comprises;

(i) means to provide a unique interrogation address to a mobile phone in response to a request by the mobile phone to establish a wireless call,

(ii) means to receive a unique mobile phone code word provided by the mobile phone in response to the unique interrogation address,

(iii) memory means for storing a plurality of sets of unique expected code words, wherein each set of expected code words is identical to a set of unique code words stored in memory means in each mobile phone,

(iv) means to compare the expected code word corresponding to the interrogation address with the received unique mobile phone code word, and

(v) means to allow the connection of a wireless call only when the unique mobile phone code word is the same as the expected code word and for disallowing the connection of a wireless call when the unique mobil phone code word and is not the same as the expected code word.

14. The wireless-based communications system of claim 13 wherein the base station further comprises:

(b)(vi) means for changing the unique interrogation address prior to a subsequent verification whereby the unique code word from the mobile phone memory means and the expected code word from the base station memory are changed from prior verifications.

15. The wireless-based communications system of claim 14 in which the address changing means is an incremental counter.

16. The wireless-based communications system of claim 14 in which the address changing means is a pseudo-random number generator.

17. The wireless-based communications system of claim 14 wherein the base station further comprises:

(b)(vii) means for informing the mobile phone that the requested wireless call has been denied.

18. The wireless-based communications system of claim 17 wherein the base station further comprises:

(b)(viii) means for counting the number of failed verifications within a preset time period; and

(b)(ix) means for alerting the service provider when the number of failed verifications within a preset time period is more than a preset amount.

19. A method for a base station in a wireless telephone system to automatically verify the identity of a mobile phone prior to connecting the mobile phone with a dialed phone, the method comprising the steps of:

(a) receiving a request by the mobile phone to the base station to connect with the dialed phone;

(b) providing to the base station from the mobile phone a mobile phone number dedicated to the mobile phone for identifying to the base station the particular mobile phone requesting the phone call;

(c) fetching from memory in the base station an expected PIN and an expected electronic serial number corresponding to the received mobile phone number;

(d) transmitting a unique interrogation address from the base station to the mobile phone;

(e) implementing in the base station a predetermined algorithm to generate an expected code word as a function of the unique interrogation address and the expected PIN;

(f) implementing in the mobile phone the predetermined algorithm to generate a code word as a function of the unique interrogation address and the mobile phone PIN;

(g) encrypting in the mobile phone a first message as a function of the electronic serial number and the generated code word and a second message as a function of the dialed phone number and the generated code word;

(h) transmitting the first and second encrypted messages to the base station;

(i) deciphering in the base station the received messages by using the expected code word to obtain a deciphered electronic serial number and a deciphered dialed phone number;

(j) verifying that the expected mobile phone number fetched from the base station memory is the same as the deciphered electronic serial number;

(k) connecting the wireless call with the deciphered dialed phone number only when verification passes; and

(l) disallowing the phone call when the verification fails.

20. The method of claim 19 comprising the additional step of:

(m) changing the unique interrogation address prior to a subsequent verification whereby the unique code word generated by the algorithm in the mobile phone and the expected code word generated by the algorithm in the base station are different from prior verifications.

21. The method of claim 20 in which the interrogation address changing step is effected incrementally.

22. The method of claim 21 in which the interrogation address changing step is effected pseudo-randomly.

23. The method of claim 20 comprising the additional step of:

(n) informing the mobile phone that the requested wireless call has been denied.

24. The method of claim 23 comprising the additional steps of:

(o) counting the number of failed verifications within a preset time period; and

(p) alerting the service provider when the number of failed verifications within a preset time period is more than a preset amount.

25. In a wireless-based communications system having a base station and at least one mobile phone, apparatus for automatically verifying the identity of a mobile phone prior to connecting a requested wireless call comprising:

(a) means in the mobile phone to request the connection of a wireless call;

(b) means in the mobile phone to provide to the base station a mobile phone number dedicated to the mobile phone for identification of the particular mobile phone requesting the call;

(c) memory means in the base station for storing an expected PIN and an expected electronic serial number corresponding to the mobile phone number for each mobile phone in the system;

(d) means in the base station to generate and transmit a unique interrogation address in response to the mobile phone request;

(e) means in the base station to implement a predetermined algorithm to generate an expected code word as a function of the unique interrogation address and the expected PIN corresponding to the mobile phone number received from the mobile phone;

(f) means in the mobile phone to implement the predetermined algorithm to generate a code word as a function of the unique interrogation address received from the base station and of the mobile phone'"'"'s PIN;

(g) means in the mobile phone to encrypt a first message as a function of the electronic serial number and the generated code word and a second message as a function of the dialed phone number and the generated code word;

(h) means to transmit the first and second encrypted messages to the base station;

(i) means in the base station to decipher the received encrypted messages by using the expected code word to obtain a deciphered electronic serial number and a deciphered dialed phone number;

(j) means in the base station to verify that the expected electronic serial number fetched from the base station memory is the same as the deciphered electronic serial number;

(k) means in the base station to connect the wireless call with the deciphered dialed phone number only when verification passes and to disallow the wireless call when the verification fails.

26. The wireless-based communications system of claim 25 further comprising:

(l) means for changing the unique interrogation address prior to a subsequent verification whereby the unique code word generated by the algorithm in the mobile phone and the expected code word generated by the algorithm in the base station are different from prior verifications.

27. The wireless-based communications system of claim 26 in which the address changing means is an incremental counter.

28. The wireless-based communications system of claim 26 in which the address changing means is a pseudo-random number generator.

29. The wireless-based communications system of claim 26 further comprising:

(m) means for informing the mobile phone that the requested wireless call has been denied.

30. The wireless-based communications system of claim 29 further comprising:

(n) means for counting the number of failed verifications within a preset time period; and

(o) means for alerting the service provider when the number of failed verifications within a preset time period is more than a preset amount.