Seems very "digital" for something intended for use by "two humans". I mean, given that you start with "sit in front of the same computer", you have a world of solutions available to you that don't involve web pages, QR codes, authenticator apps, and mobile phones. It seems like it'd make the most sense to simply exchange a one time pad while you're together, giving you the ultimate protection. If you absolutely *must* use technology, you can store a ton of data *offline* on a microSD these days, or stick with paper if you really want to be fully analog. Parents even do something like this with their kids, giving them a "secret word" that they can use to challenge an unfamiliar adult. 4597cc1b0719d120e45cdb516daaab2b6b09166b5630ef9cfaeeb9476924f3e5