We were inspired by LiFi and its ability to restrict access to only those within line of sight. Rather than sitting around waiting for it to come out we decided to build our own consumer facing application called Secret Tunnel.
What it does
Secret Tunnel allows people to wirelessly transfer pictures, text, and any other data without WiFi, cellular data, bluetooth, or NFC. Both phones are in airplane mode. How is this possible? We use the visible light spectrum to send data at the speed of light from one phone to another. We split up the data into a series of byte streams and invented our own protocol to stream the data into the camera of the receiving phone.
How we built it
We invented our own protocol to break up and send the data over the visible light spectrum by combining QR Codes and Hashing.
Challenges we ran into
There were issues with the cameras on our androids not behaving correctly, and autofocusing. We also had to do a lot of trial and error to find a tweak our system to maximize bandwidth and reliability.
Accomplishments that we're proud of
We created our own custom protocol to transfer this data over a brand new meduim that the phones were never designed for! also created a system that is significantly more difficult to hack than traditional data transfer protocol since there is no middle man and potential attackers are forced to be physically close to the devices
What we learned
We learned alot about how to program in android, as well as intimate knowledge about QR codes. Also learned about the techinical limitations of our phones cameras and processing power.
What's next for Secret Tunnel
We already deployed our app on the play store. Link: https://play.google.com/store/apps/details?id=shit.cool.backchannel Next we need to increase both speed and reliability for our platform.