[Cryptography] Explaining PK to grandma

[John Kelsey]

All the user of the email system needs to know is that:

a.  Email to a given address can only be read by the owner of the address.

b.  Nobody can tell how much email you send or receive, or to/from whom.  

It's as silly to expect most users to understand the crypto underlying this as it is to expect them to understand the financial instruments and markets that make their credit card accounts possible, or the power distribution network that keeps their lights on, or the mechanism of action of the medicine their doctor gave them for high blood pressure.  Most people find that stuff boring, many aren't bright enough to understand it very well, and nobody, no matter how bright and interested, has the time and energy to understand more than a tiny fraction of the stuff they use every day in any depth.  

--John