On 2/11/16, Phillip Hallam-Baker wrote:

On Thu, Feb 11, 2016 at 2:12 PM, John Levine wrote:

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A,B) Anyone with a QC could use it to break the keys of the wallets holding $500 million.

Which is under 5% of the NSA's annual budget. Also keep in mind that bitcoins are extremely illiquid. The largest bitcoin transaction I can find where the buyer got something of identifiable value was a $500K villa in Bali. (The so-called $147M transaction doesn't count since there's no evidence of goods or services on either side of it.) Fencing a thousand villas seems pretty hard.

If I wanted to use my NSA connections or my quantum computer to enrich myself, this doesn't strike me as a particularly good way to go.

I was asserting that the funds would be diverted for personal purposes, not to fund the agency.

$500 million might be chump change to the agency but Hanssen defected for a lot less.

There is only one purpose for an entity to crack any currency and that's to kill it. Because any cracked wallets would instantly make worldwide headlines and the currency would go to zero within a day. Depending on the speed of the adversary, you might be able to migrate crypto fast enough to save some wallets but the losers will be throwing realworld pitchforks, that will roll all the way up the legal politik chain until the pressure is unbearable. The entity isn't going to be able to recoup its costs in a zero market. Even cracking supposedly dead wallets is risk of zero without proof of deadness, granny might still have her mitts on them and be watching every day. Since an entity full of people is unlikely to be able to keep a secret kill secret, they'd be better off accelerating mining, selling in a stable market. Perhaps that's what's happening now... ;) http://bitcoin.sipa.be/ If an entity has a crack it probably can't use it, and the same scenario applies if a rogue within it appropriates it for their own purposes. And for any independant loner who discovers it. They only have odds at a few wallets before they hit the wrong one and news breaks. And for them it will be all about the lulz. Either way, digital currencies will come and go, and are here to stay. Unless Bitcoin solves its serious scalability and anonymity issues, people will probably be slowly trading out of it into something else within the next 5-10 years anyway. If that something else is significantly better and stronger, you might see some cracking then in attempt to cash out. BTC from 1250 to sub 200 didn't seem to trigger any.