> The statements made in the linked description of this cannot be true, such as Google not being able to read what you sent them and not being able to read what they responded with.
If Google’s services can respond to queries, they must be able to read them.
If A uses a cereal box cipher and B has a cereal box cipher, B can can make sense of encoded messages A sends them, A can ask about the weather, and B can reply with an encoded response that A can decode and read. B is able to read A’s decoded query, and B knew what the weather was, and responded to A with that information.
The beautiful thing is: they are :-)