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Data Sensing and secured Data forwarding in WSN …

Data Sensing and secured Data forwarding in WSN
using MICAz motes

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  • 1. Data Sensing & Secured Data Forwarding in multi-hop Wireless Sensor Network using MICAz based motes
    Presented by
    JayantPathak (2006ECS22)
    Kumar Vikramjeet (2006ECS50)
    Under the Supervision of
    Mrs. 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 Networks
    Sensor nodes sense the data & send it upward in the network hierarchy
    Base Station logs the collective data.
    Sensor nodes/motes may act as router & perform data aggregation
  • 5. Benefits of Multi-hop network
    Access Point based Network
    Multi-hop network
    AP-based topology with maximum coverage and throughput environment is challenging.
    Range & data transfer is affected by
    - node location
    - type of house
    Multi-hop topology - design of future home wireless networks and requirements for future wifi-enabled consumer electronic devices
    - wide coverage attained by nodes location
    - implementation of mesh
  • 6. Security threats in Sensor Networks
    Adversaries 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 Intruder
    Type 1
    Type 2
    Battery consumed
    Bandwidth loss
    Data packet
    Data packet
    Attacked(packet spoofed)
    False packet
    False packet
    False packet
  • 8. Solutions of threat
    A specific frequency channel is allocated to WSN at a time which is designated by RF_Channel
    Group_id should be altered manually
    RF_Channel altered manually after regular interval
    Each 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:PkmodQ
    397mod 353=40
    3233mod 353=248
    24897mod 353=160
    40233mod 353=160
  • 13. Sensor node Architecture
    • performs tasks,
    • 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
    • 20. Micro-controller:ATMEGA 128
    • 21. Transceiver: TI CC2420 802.15.4/ZigBee compliant radio 2.4-2.48 GHz (250 kbps data rate)
    • 22. External Memory: 128K Flash
    • 23. Program + Data Memory: 4K RAM
    • 24. Programming : nesC
    • 25. Platforms: TinyOS, SOS, MantisOS and Nano-RK Support
    • 26. 2.6-3.3 V power supply
    In Context of MICAz motes
  • 27. Appropriate encryption for WSN
    Encryption security depends on Key size & No. of rounds
    Key length is limited by the limited processing power of motes
    Keysize Processing energy Battery life
    Skipjack is probable candidate
    Block size = 64 bits
    Key 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
  • 29. SKIPJACK Encryption
    SKIPJACK 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 forwarding
  • 31. Software and Hardware
    • Software :
    1: Moteworks - end-to-end enabling platform
    2: Moteview - WSN viewer
    3 : TinyOS-1.x – WSN development environment
    4: Tossim For simulation
  • What is TinyOS?
    Operating system developed by UC Berkeley
    Open Source development environment
    System, library and applications written in nesC
    nesC (network embedded system C) a component-based C
    Event-driven architecture
    High concurrency, interrupt driven
    never poll, never block
    Single shared stack
    NO kernel, process/memory management
    Sleep as often as possible to save power
  • 36. Components
    A 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 interfaces
    interface StdControl {
    command result_t init();
    command result_t start();
    command result_t stop();
    interface Clock {
    command result_tsetRate( char
    interval, char scale);
    event result_t fire();
  • 37. Commands and Events
    deposit request parameters into the frame
    are non-blocking
    need to return status
    postpone time consuming work by posting a task
    can call lower level commands
    can call commands, signal events, post tasks
    can Not be signaled by commands
    preempt tasks, not vice-versa
    interrupt trigger the lowest level events
    deposit the information into the frame
    status =callCmdName(args)
    commandCmdName(args) {
    return status;
    event EvtName(args) {
    return status;
    status =signalEvtName(args)
  • 38. Events and Tasks
    Time flexible
    Longer background processing jobs …
    Hardware event handlers
    Time critical
    Shorter 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
  • 40. Inter-Node Communication General Idea
  • 41. Header (5)
    Payload (29)
    CRC (2)
    TOS Active Messages
    // 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 network
    The address is a 16-bit value specified by “make”
    “length” specifies the size of the message .
    “crc” is the check sum
  • 42. Working
    Timer.start(REPEAT, 100)
    Post Task Filldata()
    The 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.
  • 44. Hardware Setup