pubhunt seems very limited, would it be easier to search for the public key using the hash160 first for puzz#66 then use kangaroo. Or is the difficulty to find the public key even harder then finding the actual private key. I've been searching for a Month for #66 using various methods but are we certain the range is 20000000000000000 - 3ffffffffffffffff , I don't think its on the 319 range, who has better guess to the range?
The difficulty for finding a public key that opens puzzle #66 is as difficult as trying to find the public key of a bitcoin's dead address .. or any other ordinary address .. i e: 256 bits difficulty .. so in this case brute forcing the entire 66 bit range is more likely achievable than trying to search for an unknown public key
Your second question reminds me of the doubt we heard earlier about puzzle #64, where it took too long for ppl to find the key that some even started to doubt the range entirely is wrong or intentionally misleading by the puzzle creator. Ppl tend to forget the fact that 64 bits, and even worse, puzzle #66 are too huge that it could normally take decades to find the keys within their ranges ..To give you a feel of how big the range is, a gpu with a power of 500 million keys/seconds will finish the entire 66 bits range in 2339 Years
if you ask me where the key might be located, my one and only answer is: it can be anywhere within 20000000000000000 - 3ffffffffffffffff
Meaning there is no clues here .. no narrowing down options .. no predictions .. no pattern .. we have to randomly search our way into this range until one lucky bastard among us eventually finds it.
Hope that answers your questions
I'm not a newbie in this matter.... But better with 600 MKeys/s than not looking for it at all... ^^