I'm reminded of the brief experiences I had w/ Greg Priest Dorman and his physical computing setup, which had him attaching keyboards to his hands, and displays to his glasses.
This is a really hacky/bespoke idea, and I apologize if I'm being naive, but I wonder if you might be able to string a Yubikey Nano (https://www.yubico.com/product/yk4nano/) via a USB extension cable to someplace accessible to you around your head? Someplace you could trigger it with head motion?
You'd still have to figure out integrating the Nano with your login screen, your password manager, etc, but this seems like it might maybe be a viable first step.
I thought of this when the Yubikey first came out, but apparently it needs to be your finger that makes the connection. I'm not sure if that's still the case, because like you I just assumed I could extend the key somewhere around my chin controller and then use the tip of my nose to activate the key. I believe the tip of your nose is actually fairly unique FYI.
But yes, that would be one solution and great minds think alike. :-)
The Nano at least is not fingerprint-based; it's simply a capacitance thing - any conductive thing touching it, connected to you, will be treated as a touch. I have at least one coworker who strung paperclips from their Nano to someplace convenient, and they just touch the paperclip.
As well, I just performed a test by rubbing my nose on my Nano, and it worked as intended :)
I'm pretty sure the nano just needs a poke and then it'll spit out whatever you've configured it to do. I got one and used it for a little while to unlock my computer, by just having it spit out a static password on touch. The issue with this of course is that your password is now visible in clear text just by placing the key in a USB port, opening up a text input, and then touching the key. It was convenient, but very insecure obviously. Maybe it would be useful to you though.
In fact how about this, you can have mine – for free. I never use it anymore, and if there's a chance it'll help you I'm happy to just send it your way. It's just collecting dust at this point anyway.
This is a really hacky/bespoke idea, and I apologize if I'm being naive, but I wonder if you might be able to string a Yubikey Nano (https://www.yubico.com/product/yk4nano/) via a USB extension cable to someplace accessible to you around your head? Someplace you could trigger it with head motion?
You'd still have to figure out integrating the Nano with your login screen, your password manager, etc, but this seems like it might maybe be a viable first step.