Hi,
Actually i want to do Secured Communication using Microcontroller with RF module. My main request is to use Arduino board to do encryption for data from 1st PC and send it out to other Arduino board for data decryption then only view in 2nd PC. The main aim is to make sure the security level of encrypted data must high to avoid eavesdropper.
If i am using other programming software (like Visual C++) to send data to arduino board, is it using serial communication?
I am confusing the serial communication in Arduino, as data send from PC to arduino board, will data send out through TX pin at the same time?
This is because i need to do encryption in arduino 1st only can send out, if it send out from TX pin at same time data transfer from PC to arduino board, then i can't achieve my goal d.
Thanks for ur reply, hope can get help from you. 
Anything plz correct me.