Regular non-ai brute forcing can do billions of guesses per second on a single machine. But that’s still not helpful because your estimate of “millions of possibilities” is off by several orders of magnitude. For a 128 bit key, there are 2^128 (~ 3.4 x 10^38, or 340 billion billion billion billion) possible keys. You’re not brute forcing that.
Additionally, modern crypto is not susceptible to known plaintext attacks (implied by your “if it’s a message, not that hard…” statement.) It doesn’t help you guess the answer if you know whether the encrypted message you’re attacking is a password or an English phrase.
Regular non-ai brute forcing can do billions of guesses per second on a single machine. But that’s still not helpful because your estimate of “millions of possibilities” is off by several orders of magnitude. For a 128 bit key, there are 2^128 (~ 3.4 x 10^38, or 340 billion billion billion billion) possible keys. You’re not brute forcing that.
Additionally, modern crypto is not susceptible to known plaintext attacks (implied by your “if it’s a message, not that hard…” statement.) It doesn’t help you guess the answer if you know whether the encrypted message you’re attacking is a password or an English phrase.