Code needed for encryption/decrption on same algorithm

[nitroracerz]

Hi guyz....
i am working on project that is secured data wireless communication.I am using AT89S52 as transmitter and AT89C2051 at receiver end.
This project is used to communicate or transmit a text message from one place to another place through wireless. The text message is encrypted by using the Microcontroller and the encrypted message was transmitted through wireless. At the receiver end the signal was received by the standard receiver and the analog signal was fed to the Microcontroller and it was decrypted by the Microcontroller and the message was displayed over the LCD display. We can use several receivers and the message from the transmitter can be sent to the entire receivers at the same time. Each receiver can be accessed separately by its address.The Microcontroller is used to do the above work. It gets data from the Keyboard and encrypt with an private algorithm and at the receiver end the Microcontroller decrypt it with the same algorithm and display the data over the LCD display.

please guide me through
i needed the code in c programming.............
kindly help me....
Waiting for response
Regards