Zodiac unsolved 340 cipher decryption in 2020 This is a rather general question, but I'd really appreciate your (experts, in my view) opinion on this subject.
I was wondering if, using current tech like machine learning, quantum computers and ultrafast GPUs, are we anywhere closer to deciphering the (in)famous 340-sign Zodiac letter which he sent to the press in November 1969?
I can't understand why it isn't as simple as sifting thorugh random substitution-decrypted combinations of plaintext and employing properly trained NLP neural net to select only these outputs that have the highest rating in terms of grammatical and semantic correctness also taking into account the timeframe (late 60s, early 70s frequently used words) as well as context (Zodiac was a serial killer).
I'm not thinking of trivial word salad pseudo-solutions but possible plaintext which would be deemed to convey coherent message via correct language-specific sentence building rules/structures.
It seems this is now cracked, see for example here.