This is precisely right: "Similarly, a black box obfuscator would provide a way to instantly convert any private cryptography scheme to a public one that could be performed over the Internet by strangers. In a sense, obfuscation is the key to all cryptographies."
Ciphertext is a higher-order, or simply, highly ordered, deterministically derived version of plaintext.
It's a shame that so little philosophical thought has been given to cryptography. In fact, the very concept of order appears to have been lost in all contemporary discussions. Consider Leibniz's discussion and you may see some shocking origins: http://www.labirintoermetico.com/12ArsCombinatoria/Leibniz_G...
Even if that made sense it would be wrong; secure encryption (IND-CPA) needs either state or randomness. Most popular approaches stick to using randomness.
Surely you don't mean random. At best you mean pseudo-random, but either way, the result isn't random (because after all, you'd be left with something scrambled, not encrypted). That's the entire conceptual point of cryptography.
No, I do mean random. Block ciphers, such as AES, model PRFs. One cannot get IND-CPA security by just passing the message into AES ala ECB mode. Instead, one has to use randomness, in the form of a nonce, as in CBC mode, to obtain IND-CPA security.
Sure, the resulting ciphertext is only computationally indistinguishable from random. But the point of IND-CPA security is that one can't differentiate between two encryptions of different messages. Adding randomness gives you this.
Aah, but that's the rub. The result isn't actually random, it is only "computationally indistinguishable" (or, some lower threshold, since it is only in the last few decades of the multi-millennia history of crypto that this has been true). I'm not denying that pseudo-randomness (or even in very limited cases, real randomness) is used in most varients of crypto today, rather, I am suggesting that despite this, the end result is precisely the opposite: a message so highly ordered that it is "computationally indistinguishable", merely masquerading as random.
Ciphertext is a higher-order, or simply, highly ordered, deterministically derived version of plaintext.