FairPeers: Efficient Profit Sharing
in Fair Peer-to-Peer Market Places
Giancarlo Ruffo, Schifanella Rossano
Dipartimento di Informatica
Università degli Studi di Torino
Key Question

Is P2P mature enough for a fair,
profitable, and dependable market
place infrastructure?
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
n. 2
Motivations and Target

DRM vs DRM-free
debate is turning to
a negotiation
between big
actors; What about
the “long tail”?

Centralized
markets are
efficient and
dependable. But
are they scalable
and economically
affordable for all?
We, the long tail, claim that:
P2P can significantly reduce costs, improve
scalability, and distribute the profits.
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
n. 3
P2P Distribution Model
Production
Contract between
content producer
and distributors
01010
10100
10101
Industry-side
Object digitalization
P2P digital
distribution
cycle
User-side
Distribution
01010
1000
10101
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
n. 4
P2P Roles and Interactions
Legal Owner
of the Object
owns the
rights of
Providing
Interaction
Partner
provides
Object of
Interactio
n
receives
Receiving
Interaction
Partner
facilitates the
interaction
Mediating
Service
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
n. 5
A General Revenue Framework

You can release an open platform, own the
community, acquire licences, digitalize
content and insert items in the network. But
it is not finished yet:



1° issue: No clear economic value for
owners
2° issue: No clear economic value for
providers and/or mediator
3° issue: No trivial technical solutions
Are these issues solvable in a realistic way?
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
n. 6
Features of a Fair P2P Market-Place

Security


Mechanisms against
profitable frauds and
attacks by malicious
peers


High volume of
transactions
Huge population of
users

Protecting Copyright


Legality of items traded
Other forms of licenses
can be considered as
well (e.g., GPL, CC)
Profit Sharing

Efficiency and
scalability




All the participants are
part of the revenue
model (i.e., peers
contribute with disk
space, cpu cycles or
bandwidth)
The cost of an object f
has an authoring
component Ca(f) and a
distribution component
Cd(f)
Incentives to cooperate
P2P distribution:

Roles of owners (i.e.,
author), distributors (i.e.,
merchant), and receivers
(i.e., buyer) are
interchangeable
G. Ruffo, R. Schifanella FairPeers: Efficient Profit Sharing in Fair Peer-to-Peer Market Places
Journal of Network and Systems Management (JNMS), September 2007 (to appear).
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
n. 7
FairPeers: actors and roles





A copy protected digital Object f
The Owner of object f. This relationship is given by:
 a Copyright Certificate, that binds f and its owner
The Distributor of object f, who has been delegated by
the owner by means of:
 a Distribution License, that authorizes the
distribution of the content
The Receiver of f, that buys and downloads the object
from the owner or via a (set of) licensed distributor(s)
 The receiver may become a distributor later on
Some Mediators provide basic functionalities:
 Copyright Grantor (CG): stores the authorship’s
information of all the items
 Certification Authority (CA): certifies for users’
identities (a PKI is assumed - each peer X holds a
key pair <SKX,PKX>)
 A Broker: when a token-based accounting system
with central bank is assumed
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
n. 8
FairPeers: Publishing of an Inedited Content
Owner
Copyright Grantor
f,{idf,idA,f,v,DL}SKA
CERTIFICATION REQUEST
{idf,idA,f,LS,v,DL}SKCG
COPYRIGHT CERTIFICATE
idf,idA:
f:
v:
DL:
LS:
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
content and owner identifiers
medatata
value
Delegates list
lifespan
n. 9
FairPeers: Purchasing an Item from an Owner
X
Owner
{I want idf }SKX
{Cert(f)}SKA
{credits A for Ca(f)}SKX
{License(f,X)}SKA
{credits A for Cd(f)}SKX
f
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
n. 10
FairPeers: Purchasing an Item from a Distributor
X
Y
Owner
{I want idf }SKX
{License(f,Y)}SKY
{credits A for Ca(f)}SKX
{License(f,X)}SKA
{License(f,X)}SKA
{credits Y for Cd(f)}SKX
f
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
n. 11
FairPeers: Purchasing an Item from Many
Distributors


Modern peer-to-peer systems allow multisource downloads
Trivial solution: all the sources must be
payed.



Performance deterioration (presence of a
bunch of money transfers)
Infeasible to manage pico-payments
Lottery mechanism [Rivest, 1997]:
instead of paying a fraction of distribution
cost to all the distributors, only the lottery
winner will gain all the value.
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
n. 12
Y distributors set
X
Y1
Yω
Yn
Owner
{I want idf }SKX
{License(f,Yi)}SKYi
{credits A for Ca(f)}SKX
{License(f,X)}SKA
{Y,winner indicator}SKX
fi
{The winner is Yω}SKX
{credits Yω for Cd(f)}SKX
{License(f,X)}SKA
Conclusions





Yes, P2P can significantly reduce costs,
improve scalability, and distribute the profits
This is technically feasible. Is there political
and/or economic interest?
The end of the DRM vs DRM-free debate
may give new gasoline to P2P. Be ready to
run!
Social Networking and Viral Phenomena
can be of great help for providing services
and/or modeling the domain
Please, address any further question to:
[email protected] or [email protected]
Giancarlo Ruffo, Schifanella Rossano, Università di Torino (Italy)
n. 14