Towards Decentralized and Secure
Electronic Marketplace
Yingying Chen, Naftaly Minsky,
Constantin Serban, and Wenxuan Zhang
Dept of Computer Science
Rutgers University
May 6, 2005
1
Outline

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On the nature of marketplaces, and their
conventional electronic realization.
Decentralized Electronic Marketplace
(DEM), and its implementation via LGI.
A marketplace for Airline Ticket – An
Example
Related Work
Conclusion
2
Market Place Essentials
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A venue is required for buyers and sellers
to find each other and conduct trading of
merchandise.
A degree of trust between buyers and
sellers is required.
3
Electronic vs. Traditional Marketplaces
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Traditional marketplace (e.g. Farmers Market, Shopping
Mall):
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The venue of trading is physical and characterized by geographic
proximity.
The trust is generated by traditional societal means—such as
familiarity, local laws, local customs, and local police.
Electronic marketplace:
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No geographic proximity, thus no human interaction, and no
common customs and laws.
The question is: how to regain the necessary trust among the
trading parties?
4
Conventional Approach to E-Market
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Trust is established via a central mediator that
enforces a set of rules and maintains reputation.
Example: ebay.com, pricingcentral.com/ford
Limitations:
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Very expensive to establish, if the marketplace is to
be scalable and reliable.
The rules of trading are usually implicit in the code
of the mediator, and thus quite obscure.
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The Proposed
Decentralized Electronic Marketplace
(DEM)
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Based on Law Governed Interaction (LGI)---a
decentralized coordination & access control
mechanism.
Interaction between buyers and sellers does not
involve any central mediator.
All participants in the marketplace operate via
their private controllers, all carrying the same “law
of the market”, L.
The marketplace is defined by its law.
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Airline Ticket Marketplace (overview)
Banks
Banks
Banks
Airlines
L
Buyers
L
L
L
L
L
Law
L
L
L
L
L L
Sellers
L
Certification
Authority
Auditor
L
Controller
Agent
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Some Trust Requirements
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Airline tickets cannot be forged.
Credit card submitted to a seller can be
used only for the specified payment.
Money back guarantee would be honored.
One cannot lie about his/her own
reputation.
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Implementation of DEM
seller
s
airline
al
t
bank
sell
distribute
ticket
L
L
t
credit card
check req
credit card
check resp
t
L
ba
L
t
buy
t
b
buyer
controller
agent
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Implementation of DEM
(Trading Law, Cont.)
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URL location of the law:
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Java law:
www.cs.rutgers.edu/moses/examples/marketplace/trade.java1
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Prolog law:
www.cs.rutgers.edu/moses/examples/marketplace/trade.law
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Implementation of DEM
(Performance Evaluation)
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Overhead added by a pair of controllers:
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Depend on the complexity of the law: 20 – 200 µs
Negligible over WAN
Acceptable over LAN
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Deployment
(Using Distributed TCB)
Controller Service
I
I
I
I
x
adopt(L,
m ==> name)
y
L
I
m’
L adopt(L, name)
m’’
I
Implemented by Moses Middleware
12
y
Related Work
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European SEMPER project [Wainder, M. et.al. 1996-2000]
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Proposed a secure electronic marketplace for Europe
Basic trust assumption has been that each user trusts his or
her own machine, but not the machine of the partner.
Had no continuation after the project has been completed in
2000.
Distributed Digital Commerce [Schemees, M. 2003]
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Discussed the benefits of decentralized market for digital
goods.
Studied the processes involved in digital trading and their
implementation using P2P communication
Proposed no mechanism for achieving the trust and security in
the marketplace.
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Conclusion
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Proposed the concept of DEM (Decentralized Electronic
Marketplace)
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Proof of concept provided by an implementation of the
airline tickets marketplace
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Completely decentralized, fully scalable, and lightweight.
Security and trust are provided by a single, unifying law that
governs all the transactions made through the marketplace –
in some analogy to the laws that govern the traditional
marketplaces.
Implemented in both Java and Prolog trading law
Demo will be available on the web site of LGI release
Realization of DEM needs a widely deployed
commercial controller service, to act as a distributed
trusted computing base (DTCB).
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The End
Thanks !
&
Questions ?
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