3 ms·
Firstly, your numbers are off. If the hash rate grew by 50x, we would be at 3.5 Phash/s, so the attacker would need to deploy another 3.5 Phash/s to attack the
by mrb 14y ago
Firstly, your numbers are off. If the hash rate grew by 50x, we would be at 3.5 Phash/s, so the attacker would need to deploy another 3.5 Phash/s to attack the network. And Butterfly Labs's ASIC price is $50 per Ghash/s. So it would cost $175M.
Secondly, you cannot buy $175M of ASICs from BFL; they are too small of a company.
Thirdly, by the time you design, build, and deploy ASICs yourself (12 months+[1]), the network would have grown again, maybe by another 2x/5x/10x, who knows... you would have needed to account for this by spending respectively $350M/$875M/$1.75B !
So effectively by the time the network reach 3.5 Phash/s, it will be too late.
[1] For comparison it took more than a year for the DOE to deploy the #1 supercomputer, Titan, out of commodity hardware.
- Retric 14y agoYou don't need to build more hardware than everyone else if you combine a denial of service attack at the same time. The block chain has already had issues, perhaps it will never happen again but don't assume it's impossible.
- qdog 14y agoAvalon didn't take 12 months to ship, and I know someone who claims to have one of them making money, so they appear to work. Why butterfly labs is so late, I dunno. If someone with money wanted to build asics for a 51% attack, it's possible. I'm just not sure anyone with money wants to do it right now.
- mrb 14y agoApples vs. Oranges. Avalon built and shipped 20 Thash/s in ~6 months. But it would certainly take 12+ months to do 3500 Thash/s.
- stevenrace 14y agoIt's because they originally designed around a QFN packaged chip - later switching to a flip chip BGA (FCBGA) package. There was (and is) hardware on the market that could be adapted to work - but the folks who sell hardware based AES256 applications tend to deal only in the financial/military circles. Being 'first to market' in btc ASICs didn't seem to be their top priority (much to many peoples dismay).
- tlrobinson 14y agoWell, my calculations used BFL's Mini Rig SC, which was $20 per GH/s before they increased prices ($30k for 1,500 GH/s). You would certainly need to fab your own ASICs, and at that volume economies of scale would come into play, so I don't think $20 per GH/s, or even less, is an unreasonable estimate. Current hash rate is 65,000 GH/s (I think calculated around 40 or 50), so 65,000 * $20 = $1.3M. 50x that would be $65M.