Ioana Nistoreanu

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Transaction protocols in self organizing systems
Projektarbeit

• --Ioana Nistoreanu--

Betreuer Philipp Obreiter
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Ziel

• Meine Teilnahme an das Diane-Projekt stellt sich
  als eine Mitarbeit an der Entwicklung der
  Transaktionsprotokollen vor.

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Summary

• Motivation
• Settings of Internet transactions and of
  transactions in ad hoc networks
• Transaction protocols in ad hoc environment
• Conclusion

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Motivation
In an ad hoc network, each device has to fulfill
services in the benefit of the other devices,
Limited resources ? mobile devices often tend to
reduce their cooperation, mostly in the purpose
of saving these resources.
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1. Motivation
For ex, B losses valuable resources by agreeing
to forward messages from A to C.
If A requires B to send a message to C, A should
provide at his turn a service for B , as a
compensation for the resource losses.
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1. Motivation
What happens when A agrees to fulfill the service
for B, but in return, B refuses to forward the
message to C?
Purpose Develop transaction protocols that 1.
address the special features of the ad hoc
environment 2. ensure that the transaction runs
as fair as possible for all the players
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2. Settings of transactions on the internet and
of transactions in ad hoc networks

• 2.1 Internet transactions
• exchange of valuable items over open computer
  networks
• involve multiple players which do not necessarily
  trust each other
• use protocols that ensure fairness to all
  players, provided they follow the protocol
  correctly

fair exchange either each player gets the
other player's item, or neither player does
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2. Settings of transactions on the internet and
of transactions in ad hoc networks

• Existing fair protocols
• Gradual Exchange Protocols

data1
data2

• Exchange Protocols with off line third party

data1
data2
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2. Settings of transactions on the internet and
of transactions in ad hoc networks

• Exchange Protocols with on line third party

data2
data1
A protocol to ensure fairness to all players is
not always possible or cost effective.
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2. Settings of transactions on the internet and
of transactions in ad hoc networks
If some players suffer a loss of fairness, it may
still be possible to obtain fairness by starting
a dispute ? a protocol must ensure that
sufficient evidence is accumulated during the
exchange, so that correctly behaving players win
a subsequent dispute
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2. Settings of transactions on the internet and
of transactions in ad hoc networks
2.2 Comparison
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2. Settings of transactions on the internet and
of transactions in ad hoc networks
Yes
No
? no self organization
?self organization
? commonly trusted 3rd party
? no commonly trusted 3rd party
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2. Settings of transactions on the internet and
of transactions in ad hoc networks
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2. Settings of transactions on the internet and
of transactions in ad hoc networks
2.3 Settings for ad hoc networks A fair
protocol requires a commonly trusted 3rd party
or a gradual exchange of items Solution
Use of protocols to gather evidences about the
behavior of the other players Use these
evidences within a distributed reputation
system
? no trusted instance in ad hoc networks
? resource consuming ? requires divisible items
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3. Transaction protocols in ad hoc environment
3.1 First Step -gt Simple transaction Action It
is a resource consuming activity which is benefit
for another peer Roles Initiator The entity
that processes the first step of the
transaction protocol. Responder The entity that
does not process the first step of the
transaction protocol.
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3. Transaction protocols in ad hoc environment
Two Way Protocol --Bilateral Direct Mutual
Symmetric--
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3. Transaction protocols in ad hoc environment
3.2 Implementation Protocols with states
GetSignatureCall.java OriginatorState.java
ReceipSignatureState.java ReceiverProtocol.java R
eceiveSignatureState.java ResponseSignatureCall.ja
va SendSignatureState.java SignatureCall.java Sign
atureMessage.java SignatureResponseMessage.java Si
gnatureResponseO.java SignatureResponseR.java Time
OutState.java TransactionUser1.java TransactionUse
r2.java TransmitterProtocol.java WaitSignatureStat
e.java
Suited for complex, multi players protocols
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3. Transaction protocols in ad hoc environment
3.3 Request Response Protocol TwoWayTransactionP
rotocolRiskPosition.java ? class for the initiator
valuateAndHandoverAction(chs,peerID,peerID,myAct
ion, myTID,null,dtsvp) Action receivedAction
receiveAndCheckAction(chs,peerID,peerID,myTID,nul
l, peerActionDescription) if(receivedAction
null) isif.reportTransaction(peerID,c,new
TransactionReport(false)) return
null isif.reportTransaction(peerID,c,new
TransactionReport(true))
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3. Transaction protocols in ad hoc environment
TwoWayTransactionProtocolSafePosition.java ?
class for the responder
Action receivedAction receiveAndCheckAction(chs
,peerID,peerID,myTID,null, peerActionDescription)
if(receivedAction null)
isif.reportTransaction(peerID,c,new
TransactionReport(false)) return
null boolean doAction valuateAndHandoverActio
n( chs,peerID, peerID, myAction, myTID,null,
dtsvp) isif.reportTransaction(peerID,c,new
TransactionReport(true))
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3. Transaction protocols in ad hoc environment
3.4 Second Step -gt complex transaction Action
It is a resource consuming activity which is
benefit for another peer Roles Initiator
The entity that processes the first step of the
transaction protocol. Responder The
entity that does not process the first step of
the transaction protocol.
Evidences Contract Evidence that binds its
issuer to a certain behavior during the
transaction
Receipt Evidence that proves the correct
behavior of the issuers partner
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3. Transaction protocols in ad hoc environment
Six Way Protocol --Bilateral Direct Global
Symmetric--
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3. Transaction protocols in ad hoc environment
Four Way Protocol --Bilateral Direct Global
Asymmetric
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3. Transaction protocols in ad hoc environment
3.4 Third Step -gttransactions with third
party Action It is a resource consuming
activity which is benefit for another
peer Evidences Contract Evidence that binds
its issuer to a certain behavior during
the transaction Receipt Evidence that proves
the correct behavior of the issuers
partner Roles Initiator The entity that
processes the first step of the
transaction protocol. Responder The entity that
does not process the first step of the
transaction protocol.
Third party An entity that assists the
transaction peers in performing the
transaction.
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3. Transaction protocols in ad hoc environment
Two Way Protocol --Bilateral Indirect Global
Symmetric--
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3. Transaction protocols in ad hoc environment
6 Way Protocol--Bilateral Indirect Global
Symmetric
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3. Transaction protocols in ad hoc environment
6 Way Protocol--Bilateral Indirect Global
Symmetric
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4. Conclusion
Protocols 2Way Protocol without 3rd party 2Way
Protocol with 3rd party 4Way Protocol 6Way
Protocol without 3rd party 6Way Protocol with 3rd
party
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Annexe1 Transaction Protocols with defection
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Annexe1 Transaction Protocols with defection
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Annexe1 Transaction Protocols with defection