Quote from: Andzhig on June 14, 2019, 03:30:43 AM

Well, what is the sacramental meaning of the step through 5? And he just brute force? because, it seems, it is necessary that the address be translated to its public key lit up. Arulbero could not until there is no output, find the number or could?)).

The author of the puzzle did that transaction to spend from every fifth address.

My guess is that it is an experiment to see how far people can get when there is an available spend transaction versus addresses with no available spend transaction.

He has been known to visit this thread. Perhaps he will explain it.

Obviously it is much easier to get the private key when there is a spend transaction on the address. #1 through #61 took a long time whereas #65, #70, #75 and #80 were snatched up pretty soon after the author added the spend transaction to those addresses. I expect #85 will also be snatched up in due time.

As discussed #85, #90, #95, #100, #105, #110 are all within the realm of possibility given enough time and resources. It looks as if #115 would be a new world record so someone with enough equipment and motivation can probably get that one. Beyond that it is very iffy.

Note that since there is a spend transaction on these addresses we will probably see more of them before we ever see the next address without a spend transaction, #62. This is a HUGE difference in effort.

I think one of the take home messages here might be that due to this difference in effort and other factors having to do with privacy and the fungiblity of Bitcoin in general: do not reuse Bitcoin addresses. Bitcoin addresses should be used exactly twice: once to fund them and once to spend them - then never used again.