As a non-American, I have never heard any of those “trade-names” and wouldn’t know what you’re talking about.

To put it simply, one party openly distributes keys that can ONLY ENCRYPT but not decrypt a message. So I can encrypt a message but only the original key distributor can decrypt it. Thats how a first secure communication is established that can then be used to exchange any initial secrets for further communication…

Thats like saying “free refills dont exist, you pay for them beforehand”.