Bitcoin Forum

How many private keys are possible? I mean, I understand that it's a very large number, but I was mining for some vanity addresses and I started to wonder about the feasibility of saving every generated private/public key pair in a database and checking that against the list of transactions from known accounts. I get that the odds of having a match are impossibly low, but I wanted to make some actual stats to think over. With the rate of account creation and disposal, could this sort of attack be feasible in the future? Goes against my code of ethics, but I still wonder.

more than you can possibly imagine ;)

theres a calculation after which we would need all the energy resources in the universe to build a computer powerful enough.

Do you have a link?

I mine for vanity addresses and I've checked thousands and thousands of them. Literally 10s of thousands of them.
I have NEVER found one in use. I mine for very common vanity addresses... 1eBay, 1Coin, 1BTC... never ever found a used one.

I'm an honest monkey. I wouldn't steal found coins. But who knows how some honest monkey would react if they stumbled on an account with hundreds or thousands of coins? They say locks only keep the honest people out. Open doors change people.

Basically, even with all the computing power in the world at your disposal, you wouldn't (on average) find a key containing someone else's Bitcoins before the universe completely burnt out.

David Perry/enmaku(?) just wrote about this: http://codinginmysleep.com/stealing-bitcoins-the-hardest-way/

That's really impressive. I'll keep feeling safe until SHA256 fails, then.

Initially I thought, "This paper does not address vanity bitcoin addresses." but of course it does. Because they don't just happen, you still have to search every possible address until you find your target.

Still...  all a gambler sees is "blah blah blah blah" there is a chance "blah blah blah"

;)

Hehe, check this out :)

https://bitcointalk.org/index.php?topic=107172.0

http://www.youtube.com/watch?v=gqdNe8u-Jsg#t=82s

I've been thinking of saving my private keys (even old ones) just in case they get some coins. But beyond several thousand keys, and that will take too long for a live update. You may want to make a program (and there are already several) that analyzes the block chain against your list of keys, and you only do this operation once a year. It's not really a good idea to use the "wallet balance" app on the android market (google play store) to check the balance of 1 million keys.

I'm sure someone will come up with a PC (desktop) version that works offline so I don't DOS blockexplorer.com with my list of keys.

This could be fairly easily added to the Satoshi client but will require an additional index (and is not currently a priority).

I have already offered a 10BTC bounty for a successful pull request (i.e. one that is pulled into the master branch by the dev team) that will accomplish this. Maybe if others want to add to this bounty we could get this feature added sooner rather than later.

It would have to be a separate app, like part of bitcoin tools, or something. Like you said, it's not a priority for the satoshi client.

In theory, you could just add each private key or maybe you can make a pull request for bulk adding of private keys instead of one at a time. That would accomplish basically the same thing. Then you do a rescan with your 1 million key wallet. (That would make it a nice target, so better encrypt that.)