The Target Value for Bitcoin is $100K to $1M

Re:The Target Value for Bitcoin is $100K to $1M by DanBC on Wednesday March 06, 2013 @04:08AM (#5330217)

> Also, Even though Bitcoin cant be destroyed in a physical sense, it can still be completely devalued by litigation. The US has shown they are serious about anti-gambling and if this starts taking off, they simply need to go after the exchanges. Making it hard to buy bitcoins = BTC value goes down. Making it hard to sell (remember when pokerstars was shutdown? Everyone withdrew everything from ALL sites) and the value goes down catastrophically fast.

And if they were really serious they could 'just' devote some computing time to destroying the blockchain.

5 of the top 10 (out of the Top500) computers are in the US. If they were really serious they'd spend the money and burn the time and own the block chain.

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Re:The Target Value for Bitcoin is $100K to $1M by zumth on Wednesday March 06, 2013 @04:14AM (#5330233)

Top500 computers could have done this sort of attack when CPU and/or GPU mining was all the hype, but now with FPGAs and ASICs, the hardware required to have an impact is too specialized for any sort of general-purpose computing.

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Re:The Target Value for Bitcoin is $100K to $1M by mrb on Wednesday March 06, 2013 @04:46AM (#5330343)

That is correct. All of the Top500 computers combined, all 500 of them, would not be sufficient to perform a majority attack on the Bitcoin block chain.

The global network hash rate is currently 35 Thash/s.

A typical GPU found in a supercomputer (Nvidia Tesla K10/K20/C20xx) does roughly 100-200 Mhash/s.

A typical modern CPU core does roughly 1-2 Mhash/s.

You would either need 175k-350k GPUs, or 17.5M-35M CPU cores to attack Bitcoin. If you look at the Top500 list, they have maybe a few tens of thousands of GPUs combined, and about 10M CPU cores (watch out, the core counts in the list combines CPUs and GPUs, I found this out when making sense of the numbers years ago: http://blog.zorinaq.com/?e=14 )

Plus the network hash rate is predicted to increase by at least +20 Thash/s (to 55 Thash/s total) in the next month due to Avalon finishing delivery of their first batch of ASICs. Bottom line, no, all Top500 computers combined could not attack Bitcoin.

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Re:The Target Value for Bitcoin is $100K to $1M by glomph on Wednesday March 06, 2013 @04:59AM (#5330382)

Do we not think that if the NSA were so inclined they could fire up a few thousand ASIC like computers?

(Just curious)

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Re:The Target Value for Bitcoin is $100K to $1M by mrb on Wednesday March 06, 2013 @05:24AM (#5330449)

Yes the NSA can, and has, developed custom ASIC chips. They currently do it via http://www.trustedfoundryprogram.org However I doubt the NSA will ever care about Bitcoin (their primary mission is intelligence, not breaking decentralized currencies). And by the time they do (if they do) it might be too late for them to be able to attack it (the network hash rate might have grown too much, making such an attack too costly).

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Re:The Target Value for Bitcoin is $100K to $1M by waps on Saturday March 09, 2013 @07:22AM (#5348187)

If anything Bitcoin provides a full transaction record with transaction participant IDs (even if those IDs are not names). It probably helps intelligence gathering.

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Re:The Target Value for Bitcoin is $100K to $1M by glomph on Wednesday March 06, 2013 @11:14AM (#5331854)

Thanks.

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