SEEM : Secure and energy-efficient multipath routing protocol for wireless sensor networks

1. Nidal Nasser and Yunfeng Chen • Presented By: RemyaPuthanthodiyil SEEM : Secure and energy-efficient multipath routing protocol for wireless sensor networks

2. What is a WSN ? • Mechanism of WSN • Already Proposed Protocols • SEEM: • Energy efficient • Security Introduction

3. Path consuming low power Network lifetime Consumes energy equitably Energy status of entire network is of the same order Factors considered for SEEM :

4. Client/Software architecture • No source/destination initiated route discovery • Neither proactive or reactive protocol • BS(Base Station) : • Route discovery • Route maintenance • Route selection • Periodically selects a new path based on current energy levels of node in each path SEEM :

5. Resists certain types of attacks • Worm hole and sink hole attacks • Selective forwarding attacks • Additional communication overhead for resisting attacks is low. • Network lifetime is prolonged. Advantages of using BS :

6. Dynamically updates the available energy of each node along the path based on the amount of packet being sent/received Uses the updated energy condition to periodically select a new path from multipath HOW BS performs these actions:

7. Each node routing table contains only the route to BS. BS is more powerful than sensor nodes. Thin clients(nodes), processor servers (BS) BS – queries sensing data, broadcasting control packets, routing path selection and maintenance. Assumptions of SEEM:

8. All nodes are static. • All nodes have same amount of energy at the beginning of data transmission phase. • Energy consumption for each task is known for specific application • Sensing • Communication – same amount of energy for transmission/reception • 1 bit of data – 0.01 mW • Data processing • Depends on the processor Contd.

9. Deploy all sensors. • BS broadcasts ND (Neighbors discovery) message to whole network. • Each node receiving ND : • Records the prev_hop and stores inneighbors_listin ascending order of message received time. • Changes the address prev_hop to itself. • Checks the table received_pkts for the pkt_seq_num. If received, drop. Else, store pkt_seq_num in table received_pkts and rebroadcast ND to its neighbors. Topology construction

11. BS waits for short time and broadcasts NC (Neighbors collection) • Each node receiving this msg : • Records the prev_hop and stores inneighbors_listin ascending order of message received time. • Changes the address prev_hop to itself. • Checks the table received_pkts for the pkt_seq_num. If received, drop. Else, store pkt_seq_num in table received_pkts and rebroadcast NC to its neighbors. • Time the timer send_ncr_timer to call after a random delay the function of broadcast_ncr that will broadcast the NCR(NC Reply) message

12. NC broadcast helps in identifying any neighbors that were not found during ND. • When nodes receive an NC, it replies back with an NCR (NC Reply) to BS by flooding. • In NCR, source address is set to itself and destination address to BS. • NCR consists of : • Address of the node • list that has all addresses of its neighbors.

13. NC Broadcast

14. Records the prev_hop and if not present in neighbors_list, stores it. • Changes the address prev_hop to itself. • Checks the table received_pkts for the pkt_seq_num. If received, drop. Else, store pkt_seq_num in table received_pkts and rebroadcast NCR to its neighbors. Each node receiving NCR msg :

15. NCR BROADCAST

16. BS knows all nodes neighbor’s information BS constructs a weighted graph. Weight of each node – available energy. Weights of edges starting from BS are infinite. All edges from same node has same weight. Weight= (Total power of each node)/ (power of transmitting/receiving a packet)

17. Example: sending a single bit of data- 0.01mW size of packet = 128 bytes (1000 bits) Energy for sending a packet = 10mW Assume : total energy of a node = 5000mW Weight= (5000mW)/(10mW) = 500

18. NeighborHOOD MATRIX

19. BS broadcasts enquiry for data with specific features. BS broadcasts an enquiry DE (Data Enquiry) Sensor nodes that satisfies the enquiry responds with DER (DE Reply) Nodes those do not satisfy the enquiry, rebroadcasts the DE. BS calculates shortest path to the nodes that sent DER. Shortest path – path in which total energy consumed on each node for sending a packet is least (path with minimum hops) Data transmission

20. Checks if it satisfy the enquiry. • If yes, node sends a DER by setting the next_hop to first node in its neighbors_list • If no, rebroadcast DE and saves pkt_seq_num • Nodes receiving DER forwards the DER by setting next_hop to first node in neighbors_list and prev_hop to itself • DER contains Length of data to be sent to BS Each node receiving DE :

21. Calculates shortest path to the node which sentsDER. • Shortest path has minimal sum of energy consumed for transmitting a packet. • More than 2 shortest path : use the path with maximal available power. • Shortest path calculated by : • Modified BFS algorithm (implements BFS taking into consideration of the weight) When BS receives DER:

22. Finds the shortest path Checks if weight of each node is greater than predefined level. If yes, chooses that path Else, find the next shortest path. Five levels of energy limitation – each level is half of the upper level If no path is found in the current energy limitation, it reduces 1 level If no path if found from first level to fifth, considers the node is unreachable from BS Modified BFS :

23. If no path is found to a node under a certain energy limitation doesn’t mean there is no path for other nodes under same energy limitation. Energy limitation array : contains the energy limitation for each node. After finding the path BS sends a RR packet to source which includes the selected path Node sends an ACK which contains the number of data packets going to be sent If BFS does not receive the ACK, it considers the route to be invalid and runs BFS again. EXAMPLE :

24. Energy consumed for transmitting/receiving huge amount of data cannot be neglected. If it is along a single path, disconnect network and reduce network lifetime. SEEM has multipath. BS reduces the available energy of each node on the path by one. Route maintenance :

25. Most attacks can be prevented by link layer encryption and authentication using globally shared key In SEEM, the path is selected by BS, so it can defend the attacks on routing protocols that attract traffic by advertising high quality route to BS. SECURITY :

26. Wormhole and Sinkhole attacks – lure traffic from sensor nodes to BS through the attacker • Wormhole :use private, out-of-band channel invisible to underlying sensor nodes (hard to detect) • Sinkhole : use advertised information such as min. hop count to construct topology (hard to defend) • In SEEM, BS selects a path and also BS reselects a new path according to current energy level on each node along the path. • Even if attacker is present in the path, it lasts for only a limited time. SEEM defends :

27. Selective forwarding attack : • Malicious nodes refuse to forward all or parts of a message and may drop them. • Attacker includes itself in the routing path. • SEEM prevents nodes from selecting/joining routing path. • Unique Sequence Number for each packet – If any node drops it, it will be detected by the next hop node CONTD.

28. Network simulator ns-2 150m X 150m area in adhoc manner 5 different sensor fields – 30 to 130 nodes Statis nodes and same initial energy : 1000000 mW 1 BS Transmission range of each node : 10 m Compared with Directed Diffusion protocol PERFORMANCe EVALUATION:

29. Data- centric multipath routing protocol Designed to meet the robustness, scaling and energy- efficiency requirements. Establishes energy efficient data dissemination paths between source and destination Directed Diffusion PROTOCOL :

30. Throughput : percentage of successfully received packets by BS • Control Overhead: Ratio of control packets to data simulation in one run • Control Packets: ND, NC, DE, DER • Network lifetime : time at which first node failure occurs PERFORMANCE METRICS:

31. Comparison of SEEM and directed diffusion under normal behavior:

32. COMPARISON OF SEEM and directed diffusion with 20% of malicious nodes

33. SEEM considers both energy-efficiency & security simultaneously using multipath routing It mitigates the load of client nodes & extends lifetime of network Reduces transmission delays using shortest reliable path Resists attacks by choosing the high quality route to BS CONCLUSION :