Quote from: giszmo on May 12, 2012, 05:08:17 AM

Quote from: BTC_Bear on May 12, 2012, 04:27:50 AM

Quote from: giszmo on May 12, 2012, 04:14:05 AM

Quote from: organofcorti on May 12, 2012, 03:43:57 AM

If I'd stolen coins and was worried about exchanges not accepting them, I send bitdust to as many addresses as I could an exchange refusing them would have trouble keeping the rule implemented without pissing off innocent civilians.

Oh, at first sight I was tempted to take this approach for a cure of my worries about bitcoin's anonymity.

Imagine exchanges would not refuse tainted coins right out but "untaint" them by sending the tainted fraction to a well known unspendable address (aka destroy the stolen coins). A future recipient would well notice the tainted coins but also the untainting and accept the input for full bitcoins again.

Imagine gox doing this. Who would want tainted coins? All others would follow and refuse to take tainted coins aka untaint them and demand compensation for the tainted fraction of the payment.

I could imagine such a system for the good of bitcoin as the scheme "move your coins -> claim to got hacked -> profit" would get eliminated and bitcoin would be ultimately more secure but I have a problem to decide who should judge which coins are tainted and which not.

Imagine somebody selling bitcoin and only getting 70% of the promised [dirty something]. He could claim he got hacked to piss off his business partner who would not go to a court for [dirty something].

In a case as yesterday, I see no problem to count bitcoins as stolen and therefore nonexistent/invalid. But what if the raid is discovered only 3 months later and many people already accepted them? What if gox is forced into blacklisting coins from Iran? Etc ...

I love these thought experiments but I would prefer it were easier to say once and for all coins will never be tainted. Else mining would be the only way to get clean coins for sure. Mining where I get the created coins ... from blocks without fees Wink

Well if implemented, it would be to easy to bork the system. By the nature of the system, they are forever marked but with time become but a residue. Just like 90% of Dollars have drug residue on them. You are all suspects now if you have a dollar.

What makes the idea of tainting even worse, is the ability to 'frame' others for something. i.e. 18,000 coins were supposedly stolen, the 'thief' could send 2,000 of them to a reputable person's address. The recipient will claim innocence but who is going to believe that the 'thief' just gave the coins to him? We're talking 10K about now.

So, while they are not anonymous technically, they are anonymous as far as proving anything. And if there are more than 1 'thief' if one gets caught the other can move the coins taking suspicion away from the one that was caught. All the 'what ifs' put it back into the anonymous realm, unlike getting caught with DB Cooper's loot.

Let me guess: You did not read my post?

If your account A with 98 BTC receives 2 blacklisted/stolen BTC then A contains 100 BTC.
When you now send 50 BTC from A to G at MtGox, they could send 1 BTC to /dev/null and add 49 BTC to your balance.

Now if they cash out 10 BTC from G to some other user, this user's client with the same blacklist could see the stolen coins but also the cleaning and accept the 10BTC for 10BTC.

Alternatively getting paid 2 BTC that are blacklisted could directly be forwarded to /dev/null and rerequest just like MtGox would do to you. If the biggest player does so, all others will do so, too.

http://www.youtube.com/watch?v=JnX-D4kkPOQ