Quote from: ByteCoin on April 01, 2012, 01:32:52 AM

Quote from: etotheipi on April 01, 2012, 01:20:04 AM

This sounds like the exact problem I was hoping to solve with Armory's signature blocks (and message signing just implemented in Satoshi 0.6.0). The only requirement is that the user's first ever deposit is with an address they exclusively own. All future deposits to their account can be through any means whatsoever.

Ok. Deal with this scenario:
1) Innocent user funds casino account with tiny number of bitcoins and provides convincing ID.
2) Innocent user's laptop is stolen or otherwise hacked by Hacker - the point being that Hacker gains access to innocent user's private key and Innocent user loses access to the private key.
3) Hacker steals lots of bitcoins and sends them to Innocent user's casino funding address.
4) Hacker withdraws the coins from Innocent user's casino account.
5) Police find out that the stolen coins went to the casino.
6) Police ask the casino to tell them who the account belongs to.
7) Police have good reason to accuse Innocent user of theft. Innocent user can't prove he doesn't control the stolen coins and a jury has good reason to believe he can.

ByteCoin

If someone steals your identity and everything you use to identify yourself, then how is it possible to avoid this? That's *kind of* what passwords are for, except that they're still pretty much pointless, since the attacker can always request the forgotten password to your email that he just stole and then access your account.

Either way, you can tie in additional security measures if you want: the webpage for sending them signed messages could require a login. Then the attacker needs your password and private key to do it.