This document describes an RF-based wireless encryption and decryption system for military applications. The system aims to protect data transmission between remotely located military units from interception. It uses a PC as a transmitter to encode messages and a PIC microcontroller at the receiver to decode them. The communication occurs via RF transmitters and receivers operating at 433.92 MHz. The receiving unit provides password protection so that the message can only be viewed if the correct password is entered.

1. RF Based Wireless Encryption and Decryption Message
transfer system for Military Applications
The need for this project arises when we want the data communication to
be protected from others. This is highly essential in the military field and
especially during war times. Because during war periods when a particular
army wants to send a message to remotely located units, which belong to
the same army, in between any person can trap the data when it is
transmitted through wireless.
Our aim of the project is to protect the data from the ensnares.
To accomplish this, we have used a PC as a sender and PIC
microcontroller as a receiver station. The message to be sent is fed in to
the computer for different units. The computer will encode the data using
generating a duplicate Character for a real one.

2. Encrypted message:
At the receiving end the PIC microcontroller will then decode the
Received data and displays the message on the display. The
communication takes place through a Wireless RF Transmitter and
Receiver operating at 433.92 MHz
we can also use CRO at the transmitting point to view the encoded data.
To ensure the security level at the receiving end we have a password
protection. Once the Message is received the unit will give an alarm
message so that one can know that the message has arrived. The he
must enter the password through the keypad. If the password matches
then he is allowed to view the data.

3. Block Diagram
Transmitter Section
RF Transmitter
434MHZ
RS232

4. Receiver Section
Digital
RF Receiver Outputs
434MHZ PIC16F877
Microcontroller
LCD Display
+5V Power Supply
Alarm Driver
4 X 3 Matrix Key Pad
Visual Alert LED
Alarm

5. Receiver Section
Digital
RF Receiver Outputs
434MHZ PIC16F877
Microcontroller
LCD Display
+5V Power Supply
Alarm Driver
4 X 3 Matrix Key Pad
Visual Alert LED
Alarm

6. Receiver Section
Digital
RF Receiver Outputs
434MHZ PIC16F877
Microcontroller
LCD Display
+5V Power Supply
Alarm Driver
4 X 3 Matrix Key Pad
Visual Alert LED
Alarm

7. Receiver Section
Digital
RF Receiver Outputs
434MHZ PIC16F877
Microcontroller
LCD Display
+5V Power Supply
Alarm Driver
4 X 3 Matrix Key Pad
Visual Alert LED
Alarm