Transcript A Trustworthy Agent Based Online Auction System

A Trustworthy Agent Based
Online Auction System
Rinkesh Patel
CIS Master Project – Spring 2006
Advisor: Dr. Haiping Xu
Online Auctions
• Most Online Auctions specialize in person-toperson activity where individual sellers or small
businesses sell their items directly to
consumers.
• In these auctions, the seller — not the site —
has the merchandise, and often, the site will not
take responsibility for any problems that may
arise between buyers and sellers.
• Ebay, Amazon, Yahoo Auctions…
Multi Agent System
• Multi-Agent System
– An intelligent agent is an autonomous computer program capable of
carrying out one or more tasks on behalf of (human) user.
– A multi-agent system is a concurrent system that contains more than
one agent.
• Agent Properties includes
– Autonomy : agents operate autonomously, having a control over their
actions and internal state
– Sociability : agents interact with other agents using some
communication language
– Reactivity : agents perceive their environment, and respond in a timely
fashion to environment changes.
– Pro- Activeness : agents do not simply act in response to their
environment, they are able to exhibit goal-directed
behavior by taking the initiative.
Outline
• Part 1: Agent Based Online Auction System
– Is a multi-agent system that facilitates online auctions on
behalf of users.
– Provides users with different default bidding strategies.
– Allows users to customize their bidding strategies
• Part 2: Trustworthy Agent Based Online Auction
System
– Introduces a Security Agent that detects real-time Shilling
Behaviors and inform to bidding agents.
– Provides a Secure Online Auction System
• Conclusions and Future Work
Objective
• Develop an online auction system using Java Agent
DEvelopment Framework (JADE).
• Provide an agent system that facilitates online
auctions on behalf of users.
• Develop a Search Agent which matches the
requirements of user from available auction items.
• Provide agents to the users with different strategies
for the bidding on items.
• Develop a Security Agent
– monitors ongoing auctions for undesired bidding patterns
– informs the other bidders for abnormal bidding behaviors
JADE
• Description of JADE
– JADE stands for Java Agent Development Framework
(www.jade.tilab.com).
– Open source platform implemented in Java (ubiquity,
portability).
– Complies with the FIPA specification.
– Supports asynchronous message passing communication.
• Features of JADE
– Agents can be distributed across machines.
– Supports agent migration.
– Includes graphical tools to monitor the agents.
JADE Behaviors
– A behavior is basically an Event Handler, a method
which describes how an agent reacts to an event: the
reception of a message or a Timer interrupt.
– The Event Handler code is placed in a method called
action. Every behavior is scheduled following a round
robin algorithm.
– Methods of the agents involving behaviours:
addBehaviour, removeBehaviour.
– Examples of Behaviours already included in JADE:
SimpleBehaviour
TickerBehaviour
ReceiverBehaviour
ParallelBehaviour
CyclicBehaviour
WakerBehaviour
SequentialBehaviour
Architecture
Server
Responsible for
creating a new
accounts and
new auctions
Main Agent
Database
Controls a
particular
auctions
Decision
Tree
Detects
Shilling
Security Agent
Auction Agent
Provide safe
and secure
auctions
Client(s)
Search Agent
Selling/Bidding
Agent
GUI Agent
Search for
auction on behalf
of user
Interacts with
other Agents
GUI
GUI for
interaction with
user
Bid/Sell on behalf
of user.
Architecture
Server
Decision Tree
Database
Auction
Agent
Main
Agent
Security
Agent
Auction
Agent
Search
Agent
GUI
Agent
Bidding
Agent
Bidding
Agent
GUI
GUI
Client#1
GUI
Agent
Client#2
Search
Agent
Auction Server
• Main Agent
– Responsible to create new users, login, create auctions and get
the list of auctions.
– Creates the Auction Agent when a new auction is added to the
system.
– Responds to the queries for items or auctions.
• Auction Agent
– In charge of the control of a particular auction.
– Users register to the auction and then send bids to the Auction
Agent. The Auction Agent notifies the registered users of the
price changes of the item.
– At the end of the auction, this agent notifies the winner and
the seller and passes control to the Main Agent.
– When the auction is over, this agent is deleted.
Auction Server
• GUI Server
– Receives commands from the user and acts correspondingly. It
doesn’t have pro-active behavior.
– It does all the actions available in the user interface.
– Updates the auction information when messages are received
from the other agents.
• Search Agent
– Responsible for searching for items on behalf of the user.
– Notifies the user when auctions of his/her desired items are
available.
• Security Agent
– Provides Safe and Secure Environment.
Auction Client
• GUI Agent
– Receives commands from the user and acts correspondingly. It
doesn’t have pro-active behavior.
– It does all the actions available in the user interface.
– Updates the auction information when messages are received
from the other agents.
• Seller Agent
– is responsible of placing auctions on behalf of the user.
• Buyer Agent
– Join the auctions on behalf of the User.
Auction Client
• Bidding Agent
– Is responsible of placing bids automatically on behalf
of the user.
– Can be configured by the user using one of the
available strategies (OneShotBid, PeriodicBid,…) or
using Custom strategies to bid on particular auction.
– Custom Strategies provide a better way to configure
bidding agents.
– User can developed any strategy on which bidding
agent will configured to work.
Class Diagram
JADE Strategies
Bidding Strategies
• How it works
– Every strategy (BidConfiguration) contains an object
behavior that extends one of the JADE Behaviors.
– Actual Bidding process happens when the action
method of the JADE behavior.
– The BidConfiguration object contains a JPanel
where the user enters the parameters for the
bidding.
– The JPanel is displayed inside a Dialog where the
user chooses the strategy with a combo box.
– Auction System Provides,
– Normal Strategy : OneShotBehavior
– Incremental Strategy : PeriodicBehaviour
Bidding Strategy
Custom Strategies
• We propose an option to create and apply bidding
strategies for bidding agent by users.
• Bidding Template:
– We have provided a standard template for custom
strategies.
• IF <Condition> THEN <Action>
– AND, OR, <,>,<=,>=
• e.g.:
– IF Start_Bid <= CURRENT_BID AND Max_Bid < MAX_BID
THEN CURRENT_BID = CURRENT_BID + FIX_BID
Customize Bidding Strategy
Bidding Procedure
• When the user enters the information for the
automatic bidding:
– The BidConfiguration object is populated with the data and
passed to the BiddingAgent.
– The BiddingAgent calls the setupBehaviour method that
registers the behaviour object contained in the
BidConfiguration.
– When the event that the behaviour is listening to happens,
the method action is called and the bidding happens.
Trustworthy Auction Client
Trustworthy Auction Server
Outline
• Part 1: Agent Based Online Auction System
– Is a multi-agent system that facilitates online auctions on
behalf of users.
– Provides users with different default bidding strategies.
– Allows users to customize their bidding strategies
• Part 2: Trustworthy Agent Based Online Auction
System
– Introduces a Security Agent that detects real-time Shilling
Behaviors and inform to bidding agents.
– Provides a Secure Online Auction System
• Conclusions and Future Work
Agent based Online Auctions
• Not Trustable
– Agent-based online auction have not yet become
popular because they are not trustable.
• e.g. one of the big concerns in online auctions is the shilling
behavior problem.
• Not Real Time
– E-Bay, the world’s leading and widely used Auction
site does not have any real time software tools to
detect shilling behaviors.
• Shill Hunter : Software used in E-Bay to check closed
auctions.
Shill Bidding
• Shill bidding is the deliberate placing of bids to
artificially raise the price of an item and is not
allowed.
• Shill bidding occurs when the seller disguises
himself as a legitimate bidder by using a second
identity or account solely for the purpose of
pushing up the sale price.
Shill Bidding Examples
• Example #
• John lists 2 boats (#1 and #2), both with a $10,000
reserve price at the same time.
On boat #1, Alison bids $6,000 on the boat, but the
Reserve Price is not met. To get the bidding higher,
John places a bid himself at $7,000, using a different
user name. Another bidder, Marlon, then bids $8000.
The item doesn’t sell successfully.
On boat #2, Dave bids $8000. John then bids $9000,
using a different user name. Dave bids $10,000 and
wins the boat.
How to do Shill Bidding
• Bidding on own Item
• Dummy Bidder
• Devoted Bidder
– With Reserve Price
– Without Reserve Price
• Bidder-to-Seller Feedback
• Short Term Bidder
• Using Bidding Agent Strategies it is possible to
replicate same behavior.
How to Spot Shilling
• Security Agent:
– Shill bidding is one of the major problems in real
time auctions
– Security agent detects patterns in ongoing auctions
which are resembles shilling behaviors, and using a
concept of decision tree agent takes decision for
degree of shilling behaviors.
– Shilling Patterns:
•
•
•
•
Devoted Bidder
Shotgun Feedback
Numerous Retraction
Concurrent Bidding
How to Spot Shilling…
•
•
•
Many bids on an auction from different users who has
0 feedback are probable suspect.
High bidder retracts bid after pumping up the bidding.
Background Check
–
•
•
•
•
Bidder has same country/server/location/terms/
registration date as auction seller.
An account that has won auctions, but never received
any feedback.
An even stronger indication is an account that has
received feedback from only this seller.
Bidders all sign up within a short period of time.
The first bid is received minutes after the auction was
listed. Usually bidder took their time to check auction
item and bidding for that.
Decision Tree
Same Account
Yes
No
First bid
Shill Bidding
Right after bid
placement
Same IP
…
No of Feedback
More
Less
Cross
…
Yes
Yes
Same IP
No
Probable Shill
Bidding
Regular
…
Feedback
No
…
…
Security Agent
• Monitors bidding behaviors in ongoing auctions
• Detects possible shilling behaviors.
• If founds any such behaviors, then informs all current
bidding agents of that auction.
• On the basis of degree of shilling behavior, Security
agent informs that agent about unfair and biased
behavior and takes possible actions.
• Upon receiving shilling behavior information in online
auctions, the bidding agent can take appropriate actions
accordingly in order to protect the users’ interests.
Security Agent
Conclusions & Future work
• Proposed a general architecture for agent-based online
auction system.
• Designed a security agent that supports detection of
shilling behaviors.
• Developed a prototype of trustworthy agent-based
online auction system.
• Will design a language that supports flexible
configuration of bidding strategies.
• Will develop a more sophisticated security agent that
can effectively and efficiently detect shilling behaviors.