A further note for everyone, unless something drastically improves with being able to use a public key, such as BSGS, Kangaroo, etc., the 67, 68, and 69 wallets, are all easier reached (time wise) now versus 135.
The lower puzzles are now very risky ... Even if someone manages to crack one of them still they could be easily stolen.
It's better not to find a solution than get it and then being robbed right away.
Please stop this wallet stealing talk. Even if unintentionally, you are creating an invitation and letting more people know.
By the way, the difficulty level of puzzle 69 and 66 is the same, puzzle 69 the first digit is 1 and known , so on . this does make it 66 bit.
Everyone needs to be aware of this risk. Attackers can intercept and change transactions before they get mined, which is a serious issue. People should know about tools like
that help secure transactions without exposing public keys, so they don't make any mistakes in the future.