Topic: Bitcoin IS anonymous - page 2. (Read 4647 times)

So you wish it to be 100% anonymous? Or?

Sounds good, please help turn this into an actual bit of pseudocode.  I give it a 1 out of 4 in its current state, no offense, but I can't write up an algorithm from it without fleshing it out some more.  What do you mean by "almost no change" and "additional analysis".

OK here is a blockexplorer link with a 14901.47 bitcoin transfer, that's pretty big.
http://blockexplorer.com/block/00000000000006770211a16cffd5ef085f3c3ed192967bb468545a8208b6dd01

following by hand we see that address 1H7otjEVe8hToKZp1pkiwy5U1Q4AoxPE61 was a one-off, received from
1C7NuqhuPhzTnga9oEgWpppNB94H6pqkcq  was 16901.47
1NiaokMExGmHc6rXnYZVC2kmNxVuBkgUpd
1MkZPvYxrfsi2oMJzLXJkeFdirnRrPY7gE
1Js9KagG6XriQwGMSnmsKAbEaAeb5SktqH
1HWyXtxDztaHQVDC3AsExkjBLb6QJEV812
1ABSwcSCem629fsyE1iSms9R2QTU8CL21p
1Em38UYdqmqXK8HtsbckL9867XL2WE73KQ
1MiBVHXdLTZXG5R7FdtxDt8gA3XPfTGtDm
13CCfvtvppQnFtQxE12sNufVa9j4WNm3v2
133eqQmq8HrGxPNiJSGFVXC9RGBjhFL66W
171utvtF4SVkgNR7VXqht5dZStn7UvJ5wL
1748UZ1VXeFqSp8qFXdGB3PM8nz5zjbqRY
1K31DMjDXJUEqQxH5LaXipyeUFZEm3KZrG   35k btc

but anyway, that goes back way into 2010... probably not the coins we are looking for

and here is the blockexplorer for my mybitcoin address, so I have one confirmed sample to work with:
http://blockexplorer.com/address/15qEeifQfkkgThE81PzaZsEkA79dvaMMXE

jgarzik, I bow to your superior knowledge on this issue.  Much respect.

However, you will always find out about a crime after the fact unless it is part of a larger criminal enterprise that is undergoing an active investigation.  Even when there is active monitoring with wiretaps, it is fairly useless in the P2P context.  This has been demonstrated by the huge proliferation of child pornography on the gnutella p2p network.  The police catch a small percentage of people sharing it, and it continues to multiply faster than it is stamped out, for almost a decade, despite continuous monitoring (dedicated, large-scale, expensive, distributed) of the P2P network in real time.

Here's the test, for you, Gavin, and whoever else knows enough about bitcoin and computer science to qualify as an expert in court.  Can you apply your theories about bitcoin not being anonymous to a real-world case.  Where are the mybitcoin, bitomat, and allinvain's bitcoins now?  Obviously, no one knows.  That's because bitcoins are anonymous.

You have publicly said and continue to maintain that they are not, and I respect that opinion as much as I respect you as a core developer.  But "keylogging, data sniffing and snarfing, network timing analysis" all presume that the investigator already has a target, has a court order in place to allow real-time monitoring of the target's electronic communication, and is monitoring that target when the crime takes place.  This is not going to happen in the real world with a real criminal but rarely, if ever.

There could be money in it for you, as an expert witness for the plaintiffs in a lawsuit against the operator(s) of mybitcoin.com, bitomat, and the allinvain malware, probably $10k to $25k, in each case though I won't be paying you so that's just a guesstimate, ballpark fee for an expert witness in a lawsuit.  Could higher if it turns out to be a $1 million lawsuit that requires your testimony.

Consider that some people that have lost bitcoin through fraud trusted the developers when they said that bitcoins were not anonymous.  That there was some way to trace them.  The time has come to prove it isn't "just theory".  Didn't Gavin Andresen go talk to the CIA about this at a hacker conference?  If you guys have any software at all to help out or are working on tracing software, now would be a good time to release it and start building some cases. 

This is such a cheesy argument. My bank knows what I buy with my credit cards, where I buy it, and how much i spent. So does your bank. Everyone's bank.


To do the same thing with bitcoin, you need to be one of two things:

1.  A skilled hacker.
2. A government agency with probable cause.

  

i often buy large amts of btc one on one with another bitcoiner here on the forum.  after he sends to me i go and deposit USD in his bank acct.  what if MyBitcoin has numerous P2P contacts like me and slowly liquidates his stolen btc.  how do you detect that esp. if he creates several wallets and routes through each of them prior?

i know of no one more motivated than MyBitcoin.

what is a dead drop?

how do you know this?  do you have access to the public addresses at which the coins are stored?  if so, please provide.

i'd consider MyBitcoin to be a very serious case.  so lets see if anyone in the near future can identify the thief.  i highly doubt it. 

this will be an excellent real world test case.

This is why it would make no sense to just encrypt bitcoin traffic as a separate overlay network.

Making use of an existing onion net such as I2P/Tor allows hiding the bitcoin traffic between other traffic. Still not 100% fool proof, as you could always do some kind of statistic analysis, but it moves it a lot more toward the tinfoil hat domain.

Anyway, the most effective way to trace people is indeed to have inside info at the exchanges. At the point where bitcoins are exchanged for bank money it's easy to ID who is behind it. From there, the network can be followed. This will become infeasible when there are people that are only paid in bitcoin and spend bitcoin and never trade, but my gut feeling is that those are really rare at this moment.

No, it's not "just theory".

By observing timing and size of network traffic bursts, one may deduce who is the sender of a bitcoin transaction, even if the network connection is encrypted.  And by default, the connection is not encrypted.

This is obviously predicated on someone already observing you, as well as actively sampling the P2P network.  If you find out about a crime after the fact, it is a lot more difficult to associate a transaction with a network address.

Other spends from the same wallet may compromise your identity, if you have ever posted a public bitcoin address somewhere.

In a closed ecosystem without ISP wiretaps and social engineering, bitcoin is highly private.  Use of dead drops, transaction delaying, mixing services and other means help increase anonymity, but are too difficult / time consuming for most people to want to use.  So we must live in the real world, where methods of discovering who is using bitcoin are already well known and used in the field today (keylogging, data sniffing and snarfing, network timing analysis, ...)

not really, they could always dead drop it.

When the coins at mybitcoin are exchanged for dollars or euros, the identity of whoever converted those coins will be known to the exchange. Until that time, the coins from mybitcoin are exactly where they have always been. There is simply no way (at the moment) for their rightful owners to access them.

What? that it's too anonymous or to little anonymous?

Seems that this is a good compromise between fully transparent and fully anonymous. It's traceable but only if you're prepared to do a shitload of work. Which means that people won't bother for anything but very serious cases.

you're right.  thats an extremely simple and highly unlikely address scenario.  even for me, someone who isn't trying to hide anything, ABC & MNO would never be used twice since a new receiving address is automatically inserted in the clipboard after every receive and any change returned from a sending address gets automatically assigned to new address.

if they used a good laundering service, you would never know for sure.

Quite easily. Using the blockchain, you can narrow down which transactions were from an ewallet by looking for transactions with almost no change. From there, some additional analysis can tell you with near certainty which addresses belonged to Mybitcoin.

You could crowdsource that for cheaper and less effort than writing an algorithm. Make a website that lets people share links to block explorer transactions that are related, and I'm sure anyone who hasn't run screaming away from Bitcoin after the issues would be glad to help out (after all, they just got fucked hard).

In fact, I bet that's probably the more likely culprit for the price tanking rather than the coins being unloaded - lots of people got fucked hard and are exiting the market. We gotta stop pretending people's coins disappearing is good for the market, or that Bitcoin is useful solely as a store of wealth.  History has shown these two statements to be bullshit.

no, not neccessarily. traffic analysis is about looking for patterns in the communications.     

for instance (and this is a extremely basic example using callsigns)

if you were to see traffic containing the following  ( > is the direction of communication):

ABC>DEF
DEF>GHI

JKL>DEF
DEF>MNO

and later you see

ABC>XQZ
XQZ>GHI

JKL>XQZ
XQZ>MNO


you can then infer that DEF is likely XQZ


of course the real world application of this gets MUCH more complex and has many more variables, this is just a very basic example. after mapping very large amounts of traffic, you can build a map of who talks to who, and when ; communication hierarchies become apparent. identities can be  revealed in relation to the known identities of others in the communication structure.

Yeah I was going to work on a program/script to figure out where all the mybitcoin coins went to track them.  Also to make a program to hook into the bitcoin p2p network and pull the IPS of the addresses they ended up at. 

Problem #1: How the hell am I supposed to know what addresses were Mybitcoin receiving addresses to begin with?  I can start a thread, but only a tiny fraction of people are going to see it or post their receiving addresses in there. 

Problem #2: The math isn't trivial, not immediately obvious to me that the algorithm will run in O(n) time.

Problem #3: those are just the first two, they seem unsolvable without many hours of time invested, and will only lead to the discovery of problem #4-?

When jgarzik talks about bitcoin not being anonymous, he is actually talking about "in theory" they are not anonymous.  In theory someone could create a companion program to track bitcoins.

In practice, I agree that they are anonymous, for now.

wouldn't you have to have revealed your identity in relation to one of the addresses?