[hannesm]

why not then print a shared secret on your business card, and use the socialist millionaires problem (https://en.wikipedia.org/wiki/Socialist_millionaire)?

edited, added some explanation: (since there's a time span between handing out your card and verifying the FP, in which your key might have get compromised... and thus the one who received the card cannot verify whether you really got compromised and needed to update your key, or an attacker intercepted with a new key)...