i've thought of all kinds of iterations with varying levels of security. the phone with BT encryption would be fine in general but that would get picked apart

i've thought of all kinds of iterations with varying levels of security. the phone with BT encryption would be fine in general but that would get picked apart for security if you actually tried to market it as secure. the really secure way I was thinking is a small touch device that could be small enough to slide into your wallet or even as a device that would live in a phone case exposed on the back of your phone. then there would be a small yubi key like dongle that you'd plug in to whatever your target device is and it would communicate over wifi. that would be like the ultra paranoid version. then you could have the iphone/android app that communicates with the dongle, the one that uses BT encryption, the one that uses a USB cable from the phone to emulate a keyboard.. options are endless. there's some features you could have like computer vision to recognize the login prompt. it's easy to get into an imaginative loop with the ideas.