Challenge and response interaction between client and server computing devices

• US 20040093372A1
• Filed: 11/09/2002
• Published: 05/13/2004
• Est. Priority Date: 11/09/2002
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Chen, Ling Tony, Morais, Dinarte, Courage, Michael
• Granted Patent: US 7,287,052 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263

Abstract

A condition on a client that is communicating with a server is determined by issuing a challenge to the client, causing the client to produce a response indicative of the condition. The server compares the response to an expected response to determine if the condition is as expected, and if not, takes appropriate action, such as terminating the connection with the client. The challenge preferably includes parameters and a code segment that causes the client to produce the response by executing the code segment. The code segment could perform a one-way hashing algorithm of a portion of memory indicated in the parameters. The server can thus determine if the client is using a modified basic input output system, modified software, pirated software, or whether other conditions exist on the client. The challenge can be changed to prevent the client from returning a false, predetermined response to the challenge.

Claims

1. A method for enabling a server computing device to detect a condition on a client computing device, comprising the steps of:

(a) sending a code segment from the server computing device to the client computing device, said code segment comprising machine instructions;

(b) executing the code segment on the client computing device, said machine instructions comprising said code segment being used by the client computing device for determining a response, based upon a condition automatically accessed on the client computing device;

(c) sending the response from the client computing device to the server computing device;

(d) on the server computing device, comparing the response received from client computing device with an expected response;

(e) initiating a predefined action on the server computing device, if the response received from the client computing device does not match the expected response, or if no response is received, indicating that an expected condition does not exist on the client computing device; and

(f) permitting further interaction with the client computing device, if the response received from the client computing device matches the expected response, indicating that the expected condition exists on the client computing device.

2. The method of claim 1, wherein the machine instructions received by the client computing device from the server computing device implement a one-way hashing algorithm of a designated portion of a memory accessible by the client computing device.

3. The method of claim 2, wherein the code segment includes at least one parameter that is used in implementing the one-way hashing algorithm.

4. The method of claim 3, wherein machine instructions that carry out the one-way hashing algorithm are included on a non-volatile memory medium that is accessed by the client computing device, using said at least one parameter included in the code segment.

5. The method of claim 2, wherein the machine instructions are executed by the client computing device to implement the one-way hashing algorithm, said machine instructions defining steps used in said algorithm.

6. The method of claim 2, further comprising the step of changing the machine instructions sent by the server computing device to the client computing device when the client computing device is again subsequently connecting to the server computing device.

7. The method of claim 6, wherein the machine instructions change by indicating a different designated portion of the memory.

8. The method of claim 7, wherein the designated portion of the memory stores at least a portion of a basic input output system for the client computing device, said expected condition not being met if a modified basic input output system has been employed on the client computing device.

9. The method of claim 2, wherein the designated portion of the memory includes a portion of a non-volatile memory medium accessible by the client computing device, and wherein said expected condition is not met unless said portion of the non-volatile memory medium is unreadable by the client computing device.

10. The method of claim 1, further comprising the step of the client computing device determining a second response related to a condition of a non-volatile memory medium accessible by the client computing device, after determining a first response for the condition on the client computing device, said response that is sent to the server computing device comprising the first response and the second response.

11. The method of claim 1, wherein the further interaction between the server computing device and client computing device comprises the step of enabling a user of the client computing device to participate in playing an electronic game online with at least one other user of another client computing device.

12. The method of claim 11, wherein the steps of claim 1 are carried out during play of the electronic game.

13. A memory medium having machine instructions for implementing steps (a), (d), and (e) of claim 1.

14. A memory medium having machine instructions for implementing steps (b) and (c) of claim 1.

15. A method for determining a condition of a client computing device for use in participating in playing an electronic game over a network through a network game playing service, comprising the steps of:

(a) transmitting a challenge from a server computing device providing the network game playing service to the client computing device, said challenge including at least one parameter for use in computing a response on the client computing device;

(b) using the parameter included in said challenge, computing a response on the client computing device, said response being related to the condition on the client computing device;

(c) sending the response from the client computing device to the server computing device;

(d) on the server computing device, comparing the response to an expected response; and

(e) terminating a connection of the client computing device to the server computing device if the response received from the client computing device does not match the expected response to the challenge, or if no response is received, indicating that an expected condition on the client computing device is not met.

16. The method of claim 15, wherein the challenge includes encoded machine instructions for computing the response on the client computing device.

17. The method of claim 15, wherein machine instructions for computing the response are included in software for the electronic game that is accessed by the client computing device for use in participating in playing the electronic game over the network.

18. The method of claim 15, wherein the challenge causes the client computing device to apply a one-way hashing algorithm to a designated portion of a memory accessed by the client computing device to produce the response.

19. The method of claim 16, wherein the designated portion of the memory stores a basic input output system for the client computing device.

20. The method of claim 19, wherein use of a modified basic input output system by the client computing device causes the response to differ from the expected response.

21. The method of claim 18, wherein the designated portion of the memory is used for storing machine instructions for playing the electronic game, said condition indicating that the machine instructions for playing the game have not been modified to provide an advantage for a user of the client computing device when playing the electronic game.

22. The method of claim 18, wherein machine instructions for playing the electronic game with the client computing device are stored on part of a non-volatile memory medium, said designated portion of the memory being a different part of the non-volatile memory medium in which machine instructions for playing the electronic game are not stored.

23. The method of claim 22, wherein the different part of the non-volatile memory is expected to be unreadable by the client computing device to confirm that the non-volatile memory includes an authorized copy of the machine instructions for playing the electronic game.

24. The method of claim 18, further comprising the step of changing said at least one parameter included in the challenge and used by the client computing device in producing the response, when the client computing device subsequently again attempts to participate in playing an electronic game over the network, said at least one parameter including initialization code for use by the client computing device in one-way hashing the designated portion of the memory.

25. The method of claim 15, further comprising the step of changing machine instructions included in the challenge for execution by the client computing device in producing the response, when the client computing device subsequently again attempts to participate in playing an electronic game over the network.

26. The method of claim 18, further comprising the step of changing the challenge so that a different designated portion of the memory is caused to be hashed by the client computing device, when the client computing device subsequently again attempts to participate in playing an electronic game over the network.

27. The method of claim 15, wherein if the response does not match the expected response, further comprising the step of causing the server computing device to thereafter preclude at least one of the client computing device and a user of the client computing device from participating in any electronic game play over the network using the server computing device.

28. A memory medium having machine instructions stored thereon for carrying out steps (a), (d), and (e) of claim 15.

29. A memory medium having instructions stored thereon for carrying out steps (b) and (c) of claim 15.

30. A server computing device employed to provide a service to a plurality of client computing devices connected to the server computing device over a network, said server computing device detecting a condition on a client computing device, comprising:

(a) a memory in which a plurality of machine instructions are stored;

(b) a network interface for coupling to the plurality of client computing devices;

(c) a processor, coupled to the memory and to the network interface, said processor executing the machine instructions to carry out a plurality of functions, including;

(i) sending a code segment to a client computing device, said code segment causing the client computing device to determine a condition on the client computing device;

(ii) receiving a response from the client computing device indicative of the condition on the client computing device;

(iii) comparing the response to an expected response for the client computing device; and

(iv) carrying out a predefined action if the response does not match the expected response, or if the response is not received, and otherwise, providing the service to the client computing device over the network.

31. The system of claim 30, wherein the code segment includes at least one parameter used by the client computing device in determining the response.

32. The system of claim 31, wherein the code segment includes machine instructions to cause the client computing device to determine the response using said at least one parameter.

33. The system of claim 32, wherein the machine instructions included in the code segment is changed over time so that the expected response changes.

34. The system of claim 31, wherein said at least one parameter included in the code segment is changed over time so that the expected response changes.

35. The system of claim 30, wherein the response determined by the client computing device indicates whether a basic input output system employed on the client computing device has been modified from an expected state.

36. The system of claim 30, wherein the response determined by the client computing device indicates whether an executable code stored in non-volatile memory accessible by the client computing device has been modified to differ from an expected state.

37. The system of claim 30, wherein the machine instructions cause the processor to include parameters in the code segment that cause the client computing device to implement a one-way hash of a designated portion of a memory accessible by the client computing device to determine the response.