Advisor: Prof. Han-Chieh Chao Student: Joe Chen Date: 2011/06/07

Introduction Related works Proposed solution Simulation Conclusion 2011/06/072

Mobile Ad hoc Network (MANET)  Without any infrastructure to set up.  Each node has the ability to forward packet. 2011/06/073

Security issue  The lack of a central server or AP(Access Point) results security problem, nodes have native trust to transmit data. 2011/06/074

More paths to transmit your data by secure way. More reliability in wireless network. Proposed scheme.  Transmit data by trusted based routing with fountain code.  Prevent enough data sniffed by malicious node.  Increase the throughput of the network. 2011/06/075

Routing protocol  Proactive Protocol (Table driven protocol)  Each mobile node broadcasts to exchange message periodically to confirm the correctness of routing tables, but that will result network overhead and power consumption 。  It will reduce the correctness of routing tables, if nodes operate the message exchanging for a long time Interval.  Representative protocol: DSDV(Destination-Sequenced Distance Vector routing protocol), each node maintains a routing tables, and the node will need more resource.  Reactive Protocol (source initiation on-demand protocol)  When a node need to transmit date to the destination node, it starts to find the path to the destination, and the route finding will stop when an available path is found.  Representative protocol:  DSR (Dynamic Source Routing, based on source routing, it will get good efficient in low mobility networks, but the increasing mobility will result bad efficient.)  AODV (Ad Hoc On-Demand Distance Vector Routing), a good candidate routing protocol, but we need it to support node-disjoint function. 2011/06/076 [1] “A Performance Comparison of Multi-Hop Wireless Ad Hoc Network Routing Protocols”, MobiCom, 1998

Disjoint multipath routing  Link-disjoint  Node-disjoint 2011/06/077 S A C B I J D S A C B I J D

Design the secure route  Authentication  Trust-based Why use trust-based routing?  Adapting trust based can be achieved by exist equipment. it will not need additional equipment and complex technology.  Compute the trust values of nodes, to make nodes have the trust with each other before they transmit date. Why need multipath?  Improve the reliability 。  Redundant path, it can reduce the number of flooding from the route request for data retransmission.  To transmit the split data(encrypted data) by different path, it will be helpful to increase the throughput. 2011/06/078 [2] “Security in mobile ad-hoc networks using soft encryption and trust-based multi-path routing”, ACM. 2007

2011/06/079 Trust value assignment where [3] "Establishing Trust In Pure Ad-hoc Networks", ACSC, 2004

Find out the two paths which are not interference to each other. 2011/06/ 需要利用 GPS 定位, 確認節 點的座標, 找出將傳輸的方向, 並透過演算法, 防止不同路徑 節點發生重複。 2. 但在路徑上有安全上的疑慮 [4] “Energy Efficient Collision Aware Multipath Routing for Wireless Sensor Networks”, ICC, 2009

To know the power condition of nodes by extend AODV, to distribute different paths. 2011/06/0711 [5] “PAMP: Power-Aware Multi-Path Routing Protocol for a Wireless Ad hoc Network”, WCNC, 以作者的舉例, 對 source 而 言, 唯一出口只有 N2, 如果 N2 出了意外, 仍必須重新再 找一次路徑, 會有潛在問題。 2. 在安全的考量上, N2 如果是 惡意節點, 將造成資訊的危 害

Fountain code  LT code (Luby Transform Codes, 2002 A.D) FF  A transformation from F 2 k to F 2 N  Raptor code (2004 A.D, RFC 5053)  Pre codes: LDPC (Low-density parity-check codes).  Transmit data by multi-paths with different trust value. Why use fountain code in MANET?  Increase the reliability of the secure route.  Reduce the overhead in the network. 2011/06/0712 [6] "Raptor codes", Information Theory, June 2006

What is digital fountain codes  A code with robust “recover” ability.  Data are broken up many components.  Redundant duplicate information is used.  Decoding with enough received components.  Without re-transmission in the network (especially good for using TCP). 2011/06/0713

Use trust value as pre-code of Raptor Code  Different priority of data will be distributed by different trust value(TV) in pre-code phase.  Depend on different TV, the pre-code will use high weight for higher trust path to transmit the data. 2011/06/0714 Raptor Codes concept

How to use fountain code in proposed algorithm  Use the “trust value of path” in “LDPC encoding” phase.  Different trust value will be used in different channel which is consecrated about security. 2011/06/0715 [3] Applications and implementation of Raptor Codes, 2007

Mechanism  Phase I  Find the trusted multi-path as security route.  One path transmit more data by higher trust-value, the other one by lower trust-value.  Phase II  Use two trusted paths to transmit for split data by using fountain code encryption. 2011/06/0716

Route algorithm 2011/06/0717 [NOTE] 1. When send data from S to D, more data will send by higher trust path, and less data will send by low trust path. 2. the data is separated in two parts with XOR encryption (or other encryption). 3. Based on AODV routing protocol Initial a security route discovery each node in the network has a trust value from it's interactive with other nodes. route_active_time = 3000ms (RFC3561, AODV route_active_time = 3000ms) a security route should has high trust-value route and low trust-value route, so that node S can send data by two path to node D var trust-valuel: from -1 to 4 -1 = malicious node, can't be trusted 0 = not trusted node, or an just join the network 1 ~ 4 = different trust values (4 is the highest) S: source node D: destination node

2011/06/0718 Pseudo code of the algorithm Procedure begin if a node joint a MANET, then assign trust value = 0; if node works normally, then increase it's trust value until 4; else decrease it's trust value until -1; end; begin if a node initial a route request, then select paths >= trust value sum >= 4; if a paths trust value = 4, then transmit data by the path; else if find 2 paths with different priority; end; Assign a trust value to a node Find 3 paths with different trust value Transmit data using fountain code (Raptor)

2011/06/0719

2011/06/0720 Primary-path tv = 1 tv = 4 tv = 2

2011/06/0721 Secondary-path Primary-path Secondary-path tv = 1 tv = 4 tv = 2 tv = 3

2011/06/0722 Primary-path Secondary-path Primary-path Secondary-path tv = 1 tv = 4 tv = 2 tv = 3 tv = 2 tv = 3 Secondary-path tv = 2

2011/06/0723 Primary-path Third-path Secondary-path Third-path Primary-path Secondary-path Third-path Secondary-path tv = 1 tv = 4 tv = 2 tv = 3 tv = 2 tv = 3 tv = 2

 The benefit of our trust-based routing protocol  Information security  Backup route  Having security without extra device or high-tech computing  Multipath, more reliability. 2011/06/0724

NS-2.34 AOMDV (node-disjoint function included) ecs.soton.ac.uk developed a fountain code implement for NS-2 (2008, 2009) 2011/06/0725

NS x1000 Nodes: 30, 40, 50, 60, 70, 80, 90 Compare: AODV, AOMDV, FTMAODV 2011/06/0726

2011/06/0727 Packet Delivery

2011/06/0728 End-to-end delay

2011/06/0729 First Path

Looking for the Fountain Code equation  References from a thesis titled "Applications and implementation of Raptor Codes“, 2007 Other References for fountain code  M. Luby and M. Watson, “Raptor Forward Error Correction Scheme for Object Delivery”, 2007 (RFC 5053)  Todor Mladenov, Saeid Nooshabadi and Kiseon Kim, ” Implementation and Evaluation of Raptor codes on Embedded systems”, /06/0730