Method and system for detecting bot scum in massive multiplayer online role playing game

• US 8,366,553 B2
• Filed: 05/28/2010
• Issued: 02/05/2013
• Est. Priority Date: 04/19/2010
• Status: Active Grant

• Current Assignee: SNU R&DB Foundation (Seoul National University)
• Original Assignee: SNU R&DB Foundation (Seoul National University)
• Inventors: Kim, Chong Kwon, Sylvain, Hilaire
• Primary Examiner(s): CUFF, MICHAEL A
• Application Number:
  US12/789,917
• Publication Number:
  US 20110256932A1
• Time in Patent Office: 984 Days
• Field of Search: 463/42, 463/29
• US Class Current: 463/42
• CPC Class Codes: A63F 13/35 Details of game servers
• CPC Class Codes: A63F 13/75 Enforcing rules, e.g. detecting foul play or generating lists of cheating players
• CPC Class Codes: A63F 13/822 Strategy games; Role-playing games A63F13/825, A63F13/828 take precedence
• CPC Class Codes: A63F 2300/5586 for enforcing rights or rules, e.g. to prevent foul play
• CPC Class Codes: A63F 2300/6027 using adaptive systems learning from user actions, e.g. for skill level adjustment

Abstract

Provided are a method and system for detecting a bot in a Massive Multiplayer Online Role Playing Game (MMORPG) online and in real time. By analyzing a communication pattern between a client and a server, the bot is detected based on parameters such as data length, inter-arrival time and data length auto correlation. Tests using respective parameters are combined to construct a global decision scheme, and thus more accurate detection results can be obtained. An integrated anti-bot defense system can be built by combining other tests such as a Turing test.

Claims

1. A method for detecting a bot in a Massive Multiplayer Online Role Playing Game (MMORPG), the method comprising:

calculating an auto correlation value on consecutive jumping windows of a user;

comparing the auto correlation value with a first threshold to increase bot'"'"'s vote by 1 when the auto correlation value is less than the first threshold; and

determining the user as a bot when the number of bot'"'"'s vote is more than a second threshold.

2. The method for detecting a bot in an MMORPG according to claim 1, wherein the second threshold is a half of all votes.

3. A method for detecting a bot in a Massive Multiplayer Online Role Playing Game (MMORPG), the method comprising:

(a-1) calculating an auto correlation value on consecutive jumping windows of a user;

(a-2) comparing the auto correlation value with a first threshold to increase bot'"'"'s vote by 1 when the auto correlation value is less than the first threshold;

(a-3) determining the user as a bot when the number of bot'"'"'s vote is more than more than a second threshold;

(b-1) counting the number of packets having an inter-arrival time over a third threshold (itthr1) among consecutive packets inputted from a user within a window having a first predetermined size, when the number of bot'"'"'s vote is less than the second threshold;

(b-2) counting the number of packets having the inter-arrival time over a fourth threshold (itthr2) among the consecutive packets;

(b-3) determining the user as a human being when the number of packets having the inter-arrival time over the third threshold (itthr1) is more than a fifth threshold (itrt1), or a ratio of the number of packets having the inter-arrival time over the fourth threshold (itthr2) and the number of packets having the inter-arrival time over the third threshold (itthr1) is less than a sixth threshold (itrt2);

(c-1) counting the number of packets having a data length over a seventh threshold (dlthr1) among consecutive packets inputted from a user within a window having a second predetermined size, when the number of packets having the inter-arrival time over the third threshold (itthr1) is less than the fifth threshold (itrt1), or a ratio of the number of packets having the inter-arrival time over the fourth threshold (itthr2) and the number of packets having the inter-arrival time over the third threshold (itthr1) is more than the sixth threshold (itrt2);

(c-2) counting the number of packets having the data length over a eighth threshold (dlthr2) among the consecutive packets;

(c-3) determining the user as the bot when the number of packets having the data length over the seventh threshold (dlthr1) is less than a ninth threshold (dlrt1), and the number of packets having the data length over the eighth threshold (dlthr2) is less than a tenth threshold (dlrt2); and

(c-4) determining the user as the human being when the number of packets having the data length over the seventh threshold (dlthr1) is more than the ninth threshold (dlrt1), or the number of packets having the data length over the eighth threshold (dlthr2) is more than the tenth threshold (dlrt2)

a half of all votes.

4. The method for detecting a bot in an MMORPG according to claim 3, wherein the second threshold is a half of all votes.