1. DETECTION AND IGNORING BLACK HOLE ATTACK IN VANET NETWORKS BASED LATENCY TIME CH. BENSAID S.BOUKLI HACENE M.K.FAROUAN 1

2. OBJECTIVESOBJECTIVES the improvements of routing protocols in vehicular networks in terms of security. detection and prevention of BLACKHOLE attack in AODV routing protocol. 2

3. What is a wireless network? Wireless network is a network set up by using radio signal frequency to communicate among computers and other network devices. Depending on the architecture Depending on the architecture with infrastructure without infrastructure Cellular Networks Ad Hoc Network 3

4. VANET NETWORKS Is a network where each mobile nodes are vehicles (smart) equipped with communication means (sensor). the VANET networks are characterized by a high mobility of nodes. The Network topology is highly dynamic. 4

5. Communication V2V Communication V2I Communication Hybride 5

6. THE ROUTING The process of moving a packet of data from source to destination. The routing protocols LOCALISATION LOCALISATION Geographic protocols ex: ex: GPSR,GSR,A-STAR Geographic protocols ex: ex: GPSR,GSR,A-STAR TOPOLOGy TOPOLOGy Hybrid protocols Ex: ZRP Hybrid protocols Ex: ZRP reactive protocols ex: AODV reactive protocols ex: AODV proactive protocols ex: DSDV proactive protocols ex: DSDV 6

7. Ad-hoc On demand Distance Vector AODV is a reactive routing protocol for wireless Ad Hoc networks. It was designed by Charles E. Perkins and Elizabeth M. Royer. Using a sequence numbers to determine the "fresh routes". AODV is composed primarily of two mechanisms: Route Discovery and Route Maintenance 7

8. Control packets: RREQ RREP RERR RREP-ACK HELLO An entry in the routing table contains: The @ destination. next hop. The distance in number of hops. N-seq destination. The expiration time of the entry in the table. Ad-hoc On demand Distance Vector 8

9. 9 b c e f g m u a d s d Hop Count RREQ ID IP destination Sequence number destination IP source Sequence number source Route Discovery (RREQ)

10. 10 s b c e f g k m o p u x a d q s d Route Discovery (RREQ)

11. 11 s b c e f g k m o p u x a d q d s Route Discovery (RREQ)

12. 12 s b c e f g k m o p u q x a d d s Route Discovery (RREQ)

13. 13 s b c e f g k m o p u x a d q s d Route Discovery (RREQ)

14. ROUTE DISCOVRY (RREP) The way back : Each node has saved the way back. The destination sends a RREP packet to the source. The source starts to send data packets 14

15. 15 s b c e f g k m o p u x a d q d S ROUTE REPLY (RREP)

16. 16 s b c e f g k m o p u x a d q d S ROUTE REPLY (RREP)

17. BLACKHOLE ATTACK N1N1 N4N4 N3N3 N2N2 N8N8 N6N6 Source Seq=9 Destination Seq=10 Attacker Seq=4294967295 Hc=2 RREQ RREP Data packet malicious node detects an active route (recovery of @ Dest ) Prepares a RREP : @ + Dest N_seq (great value ) + N_saut (small value). Sending the RREP to the neighboring node (up to come to the source node ). The source node updates its routing table and uses the new route for sending data. The attacker starts to discard packets passed it. 17

18. PROPOSED APPROACH Our approach is based on the latency time, which is the minimum delay of transmission; it refers to the time required for a packet to go from the source to the destination through a network. Whenever a node receives a RREP, it will measure the latency value by the following formula: Where: time_stamp = the time when the correspondig RREQ is sent Hop_count = the number of hops. 18

19. PROPOSED APPROACH We note that if a neighbor or a blackhole node sends a RREP, this value of latency must be equal to RREP_WAIT_TIME because the hop_count = 1. According to the AODV implementation in the NS2, the maximum value of RREP_WAIT_TIME is 1second (the time during which a source waits RREP before regeneration of a RREQ). 19

20. PROPOSED APPROACH So, if the hop_count = 1 the latency value is small. Otherwise the value of latency increases. So if the latency value is small, then the RREP is sent by a direct neighbor or a Blackhole node. After that, we will compare the difference between source and destination sequence numbers, if it is big, then the corresponding node is a Blackhole node. Our approach is presented by the following algorithm: 20

21. THE ALGORITHM 1. MT: cache table malicious nodes. 2. RT: routing table 3. Dst_seq_no: sequence number of destination 4. Src_seq_no: sequence number of source 5. SrcIP: source IP address. 6. P: RREP Packet 7. RecvReply () 8. { 9. If (srcIP ∈ MT) {drop (p);} 10. Else { 11. If (latency < 0.5) 12. If (Dst_seq_no >>> Src_seq_no) 13. { detect_blackhole (srcIP); 14. Add_in_MT (srcIP); 15. Drop (p); 16. } 17. Else {continue ;} 18. } 19. Else continue; 20. } 21

22. P ERFORMANCE E VALUATION We have conducted a simulation study using the famous Networks simulator ns2.35 to evaluate the performance of our implemented approach to: The AODV protocol. AODV protocol under attack with 3 black holes. Our proposal (approach 01) Payal [8] (approach 02) 22

23. SIMULATION PARAMATERS We have used three different urban VANET scenarios named U1, U2, and U3 from real areas of the downtown of Malaga, Spain 23

24. SIMULATION PARAMATERS 24

25. METRICS USED Packet Delivery Ratio (PDR): This parameter represents the percentage of packets delivered to their destinations.: The average latency of data packets (Delay): This is the average time required to deliver data packets from the source to the destination successfully. Additive costs (overhead): The number of divided packets controls (RREQ,RREP, RERR). Dropped packet : Number of dropped packets. 25

26. PD Fraction VS nb_ connection 26

27. End to End Delay VS nb_connection 27

28. Dropped Packet VS nb_connection 28

29. Normalized routing load VS nb_connection 29

30. CONCLUSIONCONCLUSION In this work we proposed a simple method for detecting and isolating malicious node that uses the black hole attack in AODV protocol. Our method was simulated under different conditions and shows a good performance, a maximum rate of packet delivery and a small traffic control against to the AODV under attack 30

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