Can you stop a beagle bone being photographed?

I am working on a group project to have data encrypted in a Beaglebone Black without WiFi (however, we will connect to the Internet), where you must enter a password to access it and, if the password is incorrect three times, it will. Delete all data. However, you can solve this by imagining the computer and Brute forcing the image, so I was wondering if anyone knew how to stop that.
Or if they knew otherwise stop the problem.