I thought it was obvious because I have never come across a person who hasn't dealt with the logic problem where the farmer has to get a few of his animals acro

I thought it was obvious because I have never come across a person who hasn't dealt with the logic problem where the farmer has to get a few of his animals across a river, one at a time, and must do so in a sequence where no animals will kill each other. There was some vicious animal included. I immediately recognized that problem #1 is very very same problem, but worded differently. But it sounds like you and I have different solutions...? Edit: Oh okay, I had to look up public-key cryptography. I thought you meant slip each other secret messages or something.