[userbinator]

34 bytes is equivalent to bruteforcing a 272-bit key. It's already physically impossible to do that for a 256-bit key even if you ignore everything other than incrementing the key counter itself:

https://pthree.org/2016/06/19/the-physics-of-brute-force/

[saagarjha]

But as I said, you’re not brute forcing the entire key space because you likely have an idea of at least some of the bits.