Learning to use cryptography is not at all ridiculous. Understanding that HTTPS provides a level of scrambling to traffic is totally reasonable.
I don't think GP was talking about learning modulo arithmetic and prime factorisation.
I don't think GP was talking about learning modulo arithmetic and prime factorisation.
No mention of crypto required.
Fundamental cryptographic primitives (encryption, signatures,...) don't require any advanced math to understand if you don't go into the concrete instantiations. The technical community should really try to better teach these concepts to the general public as we move further into the digital age.
The important point is that TLS is referred to as crypto in some cases, and I believe that's what the GGP was referring to. Were I writing an expository piece, sure, I might use different language, but that's not really what my reply was about.
It's important because for example it makes it clearer why they should still check the url in the address bar (and not get phished) or that the communication with the website itself is not hidden (only the content is), etc.
I would probably start there and work your way up to https :(
The answer is symmetric cryptography, and you can give a layman example of what that is. But the key word is cryptography.
what do you think you're teaching, then? Just general good practices?
A teen can be told and taught to wear a condom without explanation of the virology and biology behind the things that it helps to avoid -- similarly Grandma can learn the importance behind https without memorizing the cypher suites; it's still an aspect of cryptography.
To give another example where this comes up: keeping backups of your data is prudent. Encrypting those backups is a good idea in a lot of cases to protect your data in case of device theft. While most modern systems make this as simple as possible for the casual user it still helps the user to have a basic understanding of what’s actually going on and the implications.