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The document discusses wireless sensor networks and describes a project using MICAz motes. It covers: 1. The characteristics and applications of wireless sensor networks, including sensing data and forwarding it through multi-hop routing. 2. Security threats in sensor networks like eavesdropping and denial of service attacks, and solutions like frequency hopping and encryption. 3. The project uses MICAz motes running TinyOS to sense temperature data and forward it securely through the network to a base station. Skipjack encryption and Diffie-Hellman key exchange provide security.

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Data Sensing & Secured Data Forwarding in multi-hop Wireless Sensor Network using MICAz based motesPresented byJayantPathak (2006ECS22)Kumar Vikramjeet (2006ECS50)  Under the Supervision ofMrs. Sonika Gupta
Introduction to WSN A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants at different locations.Characteristics of WSN Very Limited Resources Unreliable Communication Unattended Operation
Wireless Sensor NetworksSensor nodes sense the data & send it upward in the network hierarchyBase Station logs the collective data. Sensor nodes/motes may act as router & perform data aggregation
APPLICATIONS Of WIRELESS SENSOR NETWORKS
Benefits of Multi-hop networkAccess Point based NetworkMulti-hop networkAP-based topology with maximum coverage and throughput environment is challenging.Range & data transfer is affected by - node location - type of houseMulti-hop topology - design of future home wireless networks and requirements for future wifi-enabled consumer electronic devicesAdvantages - wide coverage attained by nodes location - implementation of mesh
Security threats in Sensor NetworksAdversaries can easily sniff on, intercept, inject and alter transmitted data.Adversaries can Interact with networks from a distance by inexpensive radio transceivers and powerful workstations.Resource consumption attacks - Adversaries can repeatedly send packets to drain nodes battery and waste network bandwidth, can steal nodes.
Example of IntruderAttacksType 1Type 2Battery consumedBandwidth lossData packetData packetABAttacked(packet spoofed)INFalse packetFalse packetFalse packet
Solutions of threatA specific frequency channel is allocated to WSN at a time which is designated by RF_ChannelGroup_id should be altered manually RF_Channel altered manually after regular intervalEach pair of motes share different symmetric keys.All communication are encrypted symmetric keys between motes.
Diffie-Hellman Key Exchange Algorithm each side of the communication generates a private key(letter A).
Each side then generates a public key (letter B), which is a derivative of the private key.
The two systems then exchange their public keys. Each side of the communication now has their own private key and the other systems public key (letter C).
The Diffie-Hellman protocol generates “shared secrets” – identical cryptographic key shared by each side of the communication.Cont..Prime Numbers P=3 Q=353 f:PkmodQ97233AB397mod 353=403233mod 353=2484024824897mod 353=16040233mod 353=160160
Sensor node Architectureperforms tasks,
processes data and controls the functionality of other components in the sensor node.
The functionality of both transmitter and receiver are combined into a single device know as transceivers
Sensors sense or measure physical data of the area to be monitored.
The continual analog signal sensed by the sensors is digitized by an Analog-to-digital converter and sent to controllers for further processing.
Power consumption in the sensor node is for the Sensing, Communication and Data Processing.
kinds of memory are on-chip memory of a microcontroller and Flash memory
Micro-controller:ATMEGA 128
Transceiver: TI CC2420 802.15.4/ZigBee compliant radio 2.4-2.48 GHz (250 kbps data rate)
External Memory: 128K Flash
Program + Data Memory: 4K RAM
Programming : nesC
Platforms: TinyOS, SOS, MantisOS and Nano-RK Support
2.6-3.3 V power supplyIn Context of MICAz motes
Appropriate encryption for WSNEncryption security depends on Key size & No. of rounds Key length is limited by the limited processing power of motesKeysize Processing energy Battery lifeSkipjack is probable candidate Block size = 64 bitsKey length = 80 bits No. of Rounds = 32 More No. of Rounds More time needed to crack the key

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Majorppt

  • 1. Data Sensing & Secured Data Forwarding in multi-hop Wireless Sensor Network using MICAz based motesPresented byJayantPathak (2006ECS22)Kumar Vikramjeet (2006ECS50)  Under the Supervision ofMrs. Sonika Gupta
  • 2. Introduction to WSN A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants at different locations.Characteristics of WSN Very Limited Resources Unreliable Communication Unattended Operation
  • 3. Wireless Sensor NetworksSensor nodes sense the data & send it upward in the network hierarchyBase Station logs the collective data. Sensor nodes/motes may act as router & perform data aggregation
  • 4. APPLICATIONS Of WIRELESS SENSOR NETWORKS
  • 5. Benefits of Multi-hop networkAccess Point based NetworkMulti-hop networkAP-based topology with maximum coverage and throughput environment is challenging.Range & data transfer is affected by - node location - type of houseMulti-hop topology - design of future home wireless networks and requirements for future wifi-enabled consumer electronic devicesAdvantages - wide coverage attained by nodes location - implementation of mesh
  • 6. Security threats in Sensor NetworksAdversaries can easily sniff on, intercept, inject and alter transmitted data.Adversaries can Interact with networks from a distance by inexpensive radio transceivers and powerful workstations.Resource consumption attacks - Adversaries can repeatedly send packets to drain nodes battery and waste network bandwidth, can steal nodes.
  • 7. Example of IntruderAttacksType 1Type 2Battery consumedBandwidth lossData packetData packetABAttacked(packet spoofed)INFalse packetFalse packetFalse packet
  • 8. Solutions of threatA specific frequency channel is allocated to WSN at a time which is designated by RF_ChannelGroup_id should be altered manually RF_Channel altered manually after regular intervalEach pair of motes share different symmetric keys.All communication are encrypted symmetric keys between motes.
  • 9. Diffie-Hellman Key Exchange Algorithm each side of the communication generates a private key(letter A).
  • 10. Each side then generates a public key (letter B), which is a derivative of the private key.
  • 11. The two systems then exchange their public keys. Each side of the communication now has their own private key and the other systems public key (letter C).
  • 12. The Diffie-Hellman protocol generates “shared secrets” – identical cryptographic key shared by each side of the communication.Cont..Prime Numbers P=3 Q=353 f:PkmodQ97233AB397mod 353=403233mod 353=2484024824897mod 353=16040233mod 353=160160
  • 14. processes data and controls the functionality of other components in the sensor node.
  • 15. The functionality of both transmitter and receiver are combined into a single device know as transceivers
  • 16. Sensors sense or measure physical data of the area to be monitored.
  • 17. The continual analog signal sensed by the sensors is digitized by an Analog-to-digital converter and sent to controllers for further processing.
  • 18. Power consumption in the sensor node is for the Sensing, Communication and Data Processing.
  • 19. kinds of memory are on-chip memory of a microcontroller and Flash memory
  • 21. Transceiver: TI CC2420 802.15.4/ZigBee compliant radio 2.4-2.48 GHz (250 kbps data rate)
  • 23. Program + Data Memory: 4K RAM
  • 25. Platforms: TinyOS, SOS, MantisOS and Nano-RK Support
  • 26. 2.6-3.3 V power supplyIn Context of MICAz motes
  • 27. Appropriate encryption for WSNEncryption security depends on Key size & No. of rounds Key length is limited by the limited processing power of motesKeysize Processing energy Battery lifeSkipjack is probable candidate Block size = 64 bitsKey length = 80 bits No. of Rounds = 32 More No. of Rounds More time needed to crack the key
  • 28. TinySec: a link layer encryption mechanism four main aims – Access Control, Integrity, Confidentiality, Easy of use.Implements Skipjack in CBC mode. Link layer EncryptionA B
  • 29. SKIPJACK EncryptionSKIPJACK is a 64-bit codebook utilizing an 80-bit cryptovariable (Key)SKIPJACK encrypt/decrypt 4-word (64-bit) data blocks by alternating between the two stepping rules (A and B)The algorithm requires 32 steps (rounds)
  • 30. Data sensing and Data forwardingTemperatureTemperatureTemperature
  • 31. Software and Hardware Software :1: Moteworks - end-to-end enabling platform 2: Moteview - WSN viewer3 : TinyOS-1.x – WSN development environment4: Tossim For simulationHardware:
  • 33. 2: MTS 400/420 Sensor Board
  • 34. 3: MIB 520 gateway
  • 35. 4: PC What is TinyOS?Operating system developed by UC BerkeleyOpen Source development environmentSystem, library and applications written in nesCnesC (network embedded system C) a component-based CEvent-driven architectureHigh concurrency, interrupt driven never poll, never blockSingle shared stackNO kernel, process/memory managementSleep as often as possible to save power
  • 36. ComponentsA component is a black box specified by interface(s)Interfaces define a set of logically related I/O functions calledcommands and events Components use and provide interfaces Components are statically wired together based on their interfacesStdControl.nc interface StdControl { command result_t init(); command result_t start(); command result_t stop();}Clock.nc interface Clock { command result_tsetRate( char interval, char scale); event result_t fire();}
  • 37. Commands and Eventscommandsdeposit request parameters into the frameare non-blockingneed to return status postpone time consuming work by posting a taskcan call lower level commandseventscan call commands, signal events, post taskscan Not be signaled by commandspreempt tasks, not vice-versainterrupt trigger the lowest level eventsdeposit the information into the frame{...status =callCmdName(args)...}commandCmdName(args) {...return status;}event EvtName(args) {...return status;}{...status =signalEvtName(args)...}
  • 38. Events and TasksTasks:Time flexibleLonger background processing jobs …Hardware event handlersTime criticalShorter duration (hand off to task if need be)Interrupts task and other hardware handler.Last-in first-out semantics (no priority among events)executed in response to a hardware interrupt
  • 39. Data Memory Model• STATIC memory allocation!– No heap (malloc)– No function pointers• Global variables– Available on a per-frame basis• Local variables– Saved on the stack– Declared within a method
  • 41. Header (5)Payload (29)CRC (2)SyncTOS Active MessagestypedefstructTOS_Msg{// the following are transmitted uint16_t addr; uint8_t type; uint8_t group; uint8_t length; int8_t data[TOSH_DATA_LENGTH]; uint16_t crc;// the following are not transmitted uint16_t strength; uint8_t ack; uint16_t time; uint8_t sendSecurityMode; uint8_t receiveSecurityMode;} TOS_Msg;Message is “active” because it contains the destination address, group ID, and type.‘group’: group IDs create a virtual networkThe address is a 16-bit value specified by “make”“length” specifies the size of the message .“crc” is the check sum
  • 43. MIB520 USB INTERFACE BOARDThe MIB520 provides USB connectivity to the IRIS and MICA family of Motes for communication and in-system programming. It supplies power to the devices through USB bus.