Hatband: Digital Business Card

Hatband shows your contact details as a QR code. Someone points a camera at it and has your card. There is no account to make and no server to trust: nothing about you is collected, not by Hatband and not by its developer, who has no way to know that you installed it. Your card lives on your phone. So does every card you scan, and the note of where you met. Put the code on your Lock Screen and it is there before you unlock — the name only by default, and it expires. Keep more than one card if you like: a work one, a conference one, an alias under another name, each carrying only what you give it. Every card is signed. When someone you have scanned sends a new version of theirs, it is taken only if the same key signed it, so a stranger cannot rewrite a card you already hold. Nothing a scan contains opens by itself: each one is parsed strictly and screened for hidden characters,…