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PDR Keeping The Secret . Group: Adebayo Adeyemi, Joseph Hayward, Mark Kohls, Simon McAuliffe Advisor: Dennis Goeckel. What is encryption?. So, What’s wrong with it?. Encrypted transmissions can be recorded These recording can be broken Information can be sensitive for years
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PDRKeeping The Secret Group: Adebayo Adeyemi, Joseph Hayward, Mark Kohls, Simon McAuliffe Advisor: Dennis Goeckel
So, What’s wrong with it? • Encrypted transmissions can be recorded • These recording can be broken • Information can be sensitive for years • Computers are getting faster and faster
Applications • Military • Out in the field • Missions only last less than 12 hours • Sensitive can be transmitted • Many people out in the field • No knowledge of where the enemy may be • Commercial • Keep people from recording inside building • Keep signal from being recorded from outside building
Competitors • Direct link • Trunked radio system • Frequency hopping spread spectrum.
Direct Link Large Directed Antenna Heavy, Expensive • Marine tactical data system.
Trunked System Pre-known shared key needed Even UMASS has one Easily recorded with a spectrum analyzer
Frequency Hopping A pre-known shared key for communication The security can be easily broken
System Requirements • Battery life of at least 12 hours • Receive and transmit • Operate while walking • Operate up to 300 meters. • Receive signal with 95% success rate. • Voice Transmission Bandwidth • Maintain secure communications • Less than 10% interception rate • Handheld and less than 2lbs.
Proposed Solution Step 1: Send test signal to desired radio.
Proposed Solution Step 2: RX radio sends back reply signal. Friends measure this signal strength.
Proposed Solution Step 3: TX radio sends out message. Friends not in range transmit noise.
Hardware Requirements • Receiver with Signal Strength Indicator • Transmitter without interference filtering • Battery Power • 300 meter Range • Narrow band FM
Radio Diagram Transceiver Microphone Receiver Antenna Microcontroller Transmitter Speaker
Radio Choice Choice: Linx Technologies HP3
Software Requirements RX Radio TX Radio RX Radio RX Radio
Design Challenges • Noise • Appropriate Signal Threshold • Duration for transmission • Variable transmission strength • Making overall system compact • SMD vs. Through Hole components • Demonstrate functioning system • Computer display of radio activity
MDR Deliverable The goal for MDR will be to demonstrate measurement of receive signal and transmitting noise. Step 1: Send test signal to desired radio.
MDR Deliverable The goal for MDR will be to demonstrate measurement of receive signal and transmitting noise. Step 2: RX radio sends back reply signal. Friends measure this signal strength.
MDR Deliverable The goal for MDR will be to demonstrate measurement of receive signal and transmitting noise. Step 3: TX radio sends out message. Friends not in range transmit noise.