There are few ways (not comprehensive) to prove that your application is encrypting information:
- SSL Labs has a web application to test your web application's SSL implementation
- In your web browser, sites secured with HTTPS will show a green lock next to the URL like so:
- Fire up Wireshark, or a packet sniffer/analyzer of your choice, then run some data through your application that should be encrypted (login, submit a form etc...). Find the packet, follow the TCP stream, and check to ensure nothing is transmitted in plain-text.