This is pretty much the problem I'm having.

I can narrow the 68 puzzle down from.

295,147,905,179,352,825,856 Combinations to

402,120,015,509,709,217       Combinations

With a estimated 35-40% chance one will be right.

but even with 3 zeros removed its still requires a huge amount of compute.

I just assumed with only 0.15% of all possibilities needed it would take a regular 3090 like one week, but even with 8 3090s it would still take months.

I have no idea how people plan to pool mine this thing, will probably cost more in power than it is worth. unless you have a asic + low cost power and custom code.

if 8 3090s can check say 30billion keys a sec total (its not just a single 256 hash so prob cant even do that). it would take me about 140 days to check my guess.

so if you had 8000 3090 you could check every combo in 140 days estimate. From memory when I had my mining farm 60 Gpus were about $1000 a month in power but only using 100watts each, so your looking at about $200,000 a month in power or 1.2m to check every combo and also the loss in gpu value as tech devalues. Lets say 10% loss in value, or 800gpus, so like another 800k probably.

So for $2 million dollars you can crack this thing