Transaction protocols in self organizing systems

1. Transaction protocols in self organizing systems Projektarbeit : --Ioana Nistoreanu-- Betreuer: Philipp Obreiter

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

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

4. A B C 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.

5. A B C 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.

6. A B C 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

7. 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”

8. Someone called me ? 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

9. 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.

10. EVIDENCE 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

11. 2. Settings of transactions on the internet and of transactions in ad hoc networks 2.2 Comparison

12. 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

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

14. 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

15. 3. Transaction protocols in ad hoc environment 3.1 First Step -> 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.

16. 3. Transaction protocols in ad hoc environment Two Way Protocol --Bilateral Direct Mutual Symmetric--

17. 3. Transaction protocols in ad hoc environment 3.2 Implementation Protocols with states GetSignatureCall.java OriginatorState.java ReceipSignatureState.java ReceiverProtocol.java ReceiveSignatureState.java ResponseSignatureCall.java SendSignatureState.java SignatureCall.java SignatureMessage.java SignatureResponseMessage.java SignatureResponseO.java SignatureResponseR.java TimeOutState.java TransactionUser1.java TransactionUser2.java TransmitterProtocol.java WaitSignatureState.java Suited for complex, multi players protocols

18. 3. Transaction protocols in ad hoc environment 3.3 Request Response Protocol TwoWayTransactionProtocolRiskPosition.java class for the initiator … valuateAndHandoverAction(chs,peerID,peerID,myAction,myTID,null,dtsvp); ActionreceivedAction=receiveAndCheckAction(chs,peerID,peerID,myTID,null,peerActionDescription); if(receivedAction==null) { isif.reportTransaction(peerID,c,newTransactionReport(false)); returnnull; } isif.reportTransaction(peerID,c,newTransactionReport(true)); …

19. 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)); returnnull; } boolean doAction = valuateAndHandoverAction( chs,peerID, peerID, myAction, myTID,null, dtsvp); … isif.reportTransaction(peerID,c,new TransactionReport(true)); …

20. 3. Transaction protocols in ad hoc environment 3.4 Second Step -> 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 issuer’s partner

21. Six Way Protocol --Bilateral Direct Global Symmetric-- 3. Transaction protocols in ad hoc environment

22. Four Way Protocol --Bilateral Direct Global Asymmetric— 3. Transaction protocols in ad hoc environment

23. 3. Transaction protocols in ad hoc environment 3.4 Third Step ->transactions 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 issuer’s 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.

24. Two Way Protocol --Bilateral Indirect Global Symmetric-- 3. Transaction protocols in ad hoc environment

25. 6 Way Protocol--Bilateral Indirect Global Symmetric— 3. Transaction protocols in ad hoc environment

26. 6 Way Protocol--Bilateral Indirect Global Symmetric— 3. Transaction protocols in ad hoc environment

27. 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

28. Annexe1: Transaction Protocols with defection

29. Annexe1: Transaction Protocols with defection

30. Annexe1: Transaction Protocols with defection