Can’tTouchThisK

SM

Ham

mer

Jun Wei ChuahShihong Ng

Ming Yang Koh

Project Concept/Motivation

•Concept: •This project will act as deterrence against laptop thefts, providing the owner a greater degree of security.•The prototype integrates off-the-shelf embedded components, such as motion-sensing accelerometer, buzzer, RFID reader and tags for passive activation of the device and the Tmote Sensor.

•Motivation:•A laptop owner today is unable to leave his/her laptop unattended without risk of the laptop being stolen.•Using our prototype system, an alarm will be activated if the laptop is being handled by unauthorized personnel.

Competitive Analysis:

Caveo Anti-Theft PC Card:http://caveo.com/products/anti-theft.htm

•The product works by sensing motion and emitting an alarm when its moved.•Our product will automatically activate the lock when it does not sense the user’s presence

Kensingstone Cable Lock:http://us.kensington.com/html/11179.html

•The product works by physically locking the laptop to a secure object. •Our product requires less user input and is a smaller and lighter solution.

Requirements:

•Functional Requirements:•Detects the presence of the user when in range and disarms the device.•Arms the device when user is out of range.•Allows software arming and disarming of device.•Detects movement of laptop when armed and sounds alarm accordingly.

•Non-functional Requirements:•Reliability: When armed, the device will detect significant movement and sound the alarm. •Usability: The device will require minimal user input after installation.•Threshold: Non-extended small movements will be tolerated by the system. •Timing: The alarm will trigger within 5 seconds of detection of motion.

Technical Specifications:Microcontroller: Moteiv “Tmote Sky”http://www.moteiv.com/products/tmotesky.php

Buzzer: Generic “Buzzer”http://export.farnell.com/jsp/endecaSearch/partDetail.jsp?sku=1192515

$2.50 ea

Motion sensor: Freescale “MMA7260QT Accelerometer” http://www.freescale.com/files/sensors/doc/data_sheet/MMA7260QT.pdf

$5.68 ea

Rechargeable battery : Generic “3V Rechargeable Lithium Battery”http://www.action-electronics.com/batcomp.htm

Quote pending

Wireless keycard components: RFID Reader: Texas Instruments “Series 2000 Micro Reader RI-STU-MRD1”http://www.ti.com/rfid/docs/manuals/pdfSpecs/RI-STU-MRD1.pdf

Quote pending

RFID Tag: Texas Instruments “Card Transponder TRP-R4FF”http://www.ti.com/rfid/docs/manuals/pdfSpecs/TRP-R4FF.pdfQuote pending

Voltage step-up converter: Texas Instruments “TPS61027”http://focus.ti.com/docs/prod/folders/print/tps61027.html $3.15 ea

Architecture Block Diagram

State Chart for Laptop

State Chart for Microcontroller

State chart for RFID reader

Initreset

On

On

Off

Tag Found

Tag not found

Tag found

Tag not found

Tag fo

und

Tag

no

t fo

und

Initreset

Ringing

Buzzer on

Buzze

r Off

State chart for Buzzer

State chart for Accelerometer

Initreset

On

On

accelerometer

Off

acce

lerom

eter M

otion

sensin

g

List of Use Cases

Bootstrapping

Laptop

Microcontroller

Accelerometer

RFID reader

StartupStartup

Startup

Bootstrapping

TearDown

Laptop

Microcontroller

Accelerometer

RFID reader

Shutdown

TearDown

Shutdown

Shutdown

User leaves laptop User moves laptop

List of Use Cases (continued…)

RFID reader

Tag found

User moves laptop

disarm

RFID tag Microcontroller RFID reader

Tag not found

User leaves laptop

Arm

MicrocontrollerRFID tag

Start motion sensing

Accelerometer

Laptop

Start password screen

Motion sensed

Thief moves laptop

Microcontroller

Accelerometer Buzzer

Start

Laptop

Password entered

Off

Thief moves laptop User approaches

laptop

List of Use Cases (continued…)

RFID reader

Tag found

User approaches laptop

disarm

RFID tag Microcontroller

Laptop

Off password

screen

Risks

R1. Compatibility between RFID reader and Telos Motes R2. Compatibility between voltage regulator, RFID reader and

Telos Motes R3. Compatibility of rechargeable battery with rechargeable

mechanisms on Telos Motes R4. Real-world performance of RFID reader with respect to

range R5. Constraints with respect to the ports available on Telos

Motes R6. Difficulty in finding suitable algorithms differentiating

significant and non-significant movements R7. Usage under different laptop operating environments

Mitigation of Risks

Worst case usage of Zigbee protocol and Telos Motes for passive device (R1, R2, R4)

Requires device to always be plugged into laptop (R3)

Usage of 18-348 board to meet specific port requirements (R5)

Usage of multiplexers to meet port requirements (R5)

For worst case, any slight movement would trigger alarm (R6)

Requires Windows as main Operating System (R7)

Test Cases

Project Concept: Laptop Anti-theft Device Status Update:

Currently working on getting the RFID to communicate with the T-mote (certain voltage issues to sort out)

Desktop interface complete (with password screen) Project Test Cases (Testing the use cases):

Startup (Devices start up without errors) User moves laptop (Nothing should happen) User leaves laptop (Arming of device) Thief moves laptop (Alarm rings) User returns to laptop (Disarming of device) Shutdown (Devices shutdown properly)

Performance Tests Degree of movement

Important to distinguish between subtle movements and theft Test: Various movements around laptop, check correct

identification of theft Response time before buzzer sounds

When theft is detected, important to sound buzzer in a timely manner

Test: Move laptop in armed mode, check that buzzer sounds in no more than 500ms (500ms X 100m/10s = 5m)

Password security Password must be resistant to cracking Test: Look for loopholes in password system (some form of

white-box testing) RFID / Disarming range

User’s presence must be detected from a suitable distance Test: Tester moves into close proximity with the device (no more

than 50cm), check that user’s presence is detected

Testing Process

Usage of checklists for testing Useful for checking degree of movement and RFID range Useful for checking password security

Usage of software tools in testing Software timers for response time calculations (correlate

with hardware timers for accurate timings)

Testing under heavy conditions Testing RFID range in area with several RFID readers or

tags Testing with non-user RFID tags

Looking Ahead

Anticipated Difficulties Ambiguity with regards to significance of

movement RFID functionality still a blur, might switch to

Zigbee modules for authentication Thankfully, most of our test cases are pretty

straightforward Might include testing with errors to ensure

functionality Lessons learnt in testing

As mentioned before, degree of movement test is still rather shady

Difficult for author of code to check correctness (password security)

Questions? Anyone?

Status Update

Project Concept: Laptop Anti-theft Device Status Update (implementation):

Voltage incompatibility of RFID reader, as well as concerns with limited range of RFID

Using Zigbee protocol to communicate between t-motes

Achieved a satisfied level of sensitivity for device Status Update (testing):

Tested varying degrees of movement Tested range of Zigbee protocol

Experimentation plan Metrics:

Range of T-motes Sets distance at which we arm and

disarm the t-mote Degree of movement of accelerometer

Sets the degree movement to trigger off alarm

How to measure Conducted 40 trials for each metric

Measured # times in which device is constantly being armed/disarmed for 5 seconds at a particular distance

Measured # times in which alarm is sounded at the various movements

Initial data Almost every sudden movement

would cause alarm to ring Thief can steal laptop by moving it

away slowly Banging of lab table does not cause

alarm to sound off most of the times

Device will be in disarm mode constantly if user within 1.5 feet

Device will likely be in arm mode constantly if user is at 16 feet from device

% of times device was armed vs distance from device

0%

20%

40%

60%

80%

100%

Range of 1.5 feet Range of 16 feet

Distance from Device

% o

f tim

es d

evic

e w

as

arm

ed fo

r 5 s

econ

ds

% of times alarm sounded vs various degrees of movement

0%

20%

40%

60%

80%

100%

Banging of table (False positive)

Moving laptop aw aysteadily

(False negative)

Sudden movement oflaptop

Various movements

% o

f tim

es it

sou

nded

Looking forward

Lessons learnt: Subtleties in tinyOS,

Deluge library prevented buttons from working Using genericComm instead of which hpluart to send

packets Using Tosmsg->strength instead of Tosmsg->lqi

What is next? Receiving Tosmsg packets from PC Setting and testing with different mote IDs Analyze device for more appropriate sensitivities

to movements and range

Questions? Anyone?