Pertaining to the XKCD you just have to hope they don't get wise and go with vivisection. However, the sender would likely phone/email/deliver the password on

Pertaining to the XKCD you just have to hope they don't get wise and go with vivisection. However, the sender would likely phone/email/deliver the password on notification of arrival, which IIRC was what was supposed to happen in Johnny Mnemonic, but the Yakuza attacked and Johnny gets a portion of the password, which incidentally ties in with frame 2 of that comic. I guess the lesson here is that a $5 wrench and a $50 mix of acid/shrooms/K applied to the right person would beat any cyrpto known to man.