$P \ne NP$: a proof relating complexity theory to block ciphers
and the elf model proves a secure block cipher exists

It is worth mentioning that lower bounds in computationally limited settings do not &quot;lift&quot; [1] to lower bounds in computationally stronger settings. For example, there are lower bounds of $\Omega(\sqrt{|G|})$ on DL in the generic group model. This does not prove that DL is hard in &quot;real life&quot; though (and in fact, finite-field discrete log has $o(\sqrt{|G|})$ algorithms).
Secure block ciphers are not known to exist unconditionally. I don't know if your post precisely says this anywhere (this is the impression I get of the insight of your post though), but a proof that a secure block cipher exists immediately proves that $\mathsf{P}\neq \mathsf{NP}$.
This is because:

Secure Block ciphers are Pseudo-Random Permutations (PRPs)
PRPs imply One-Way Functions (is this HILL89? Idk its one of those old results)
The existence of One-Way Functions directly shows $\mathsf{P}\neq\mathsf{NP}$ (the problem of inverting a poly-time computable function is easily shown to be in $\mathsf{NP}$. The function being one-way means this can't be done in $\mathsf{P}$, and therefore we've found an $\mathsf{NP}$ language which is not in $\mathsf{P}$.


[1] There are areas of complexity theory which try to do exactly this though. Look up &quot;lifting theorems&quot; in communication complexity in particular, where lower bounds in weak models (generally things like decision trees) are &quot;lifted&quot; to lower bounds (for slightly different problems generally) in stronger models. This all being said, I do not expect lifting theorems to be useful for your application.