> number sequences which are used as symmetric encryption keys to create virtually unbreakable ciphertexts

Why should the average reader be expected to know the distinction between keys, ciphertexts, and number sequences. They're just codes.

This is AtlasObscura intended for travelers, not an academic journal.

It's like learning about functional programming and the gatekeepers explain a monad as being "a monoid in the category of endofunctors".