Silk Road forums

Discussion => Security => Topic started by: unit716 on March 21, 2012, 03:32 pm

Title: Anonymizing Bitcoins
Post by: unit716 on March 21, 2012, 03:32 pm
If I open a MtGox account using a public computer and deposit funds into a bank using bitinstant, do I really need to run my bitcoins through an anonymizer service or is it safe to go ahead and transfer them to SR?  If it isn't safe then I'm not entirely sure that I understand the point. 

Also, how do you figure out how much cash to deposit?  It seems like enough time passes between depositing money and making a purchase so the value of bitcoins fluctuates.
Title: Re: Anonymizing Bitcoins
Post by: SuperDimitri on March 21, 2012, 04:05 pm
Welcome to the underworld.
Title: Re: Anonymizing Bitcoins
Post by: Diamond on March 21, 2012, 04:29 pm
No one said this would be easy:

https://en.bitcoin.it/wiki/Anonymity
Title: Re: Anonymizing Bitcoins
Post by: unit716 on March 21, 2012, 10:41 pm
I understand what is involved in anonymizing bitcoins, but if I make a cash deposit using bitinstant into a bank account I cannot understand any purpose for going through the extra steps of anonymizing if there no way for them to be traced back to my identity anyway. 

Perhaps someone could help me out with this?
Title: Re: Anonymizing Bitcoins
Post by: QTC on March 21, 2012, 10:56 pm
I understand what is involved in anonymizing bitcoins, but if I make a cash deposit using bitinstant into a bank account I cannot understand any purpose for going through the extra steps of anonymizing if there no way for them to be traced back to my identity anyway. 

Perhaps someone could help me out with this?
if you feel you're unlinkable to your transaction log then you can ignore mixing your coins. But some people load coins is a fashion that's linkable to their ID and they need to protect themselves by blinding their own transaction log.
Title: Re: Anonymizing Bitcoins
Post by: Gigles on March 23, 2012, 05:17 am
I understand what is involved in anonymizing bitcoins, but if I make a cash deposit using bitinstant into a bank account I cannot understand any purpose for going through the extra steps of anonymizing if there no way for them to be traced back to my identity anyway. 

Perhaps someone could help me out with this?
if you feel you're unlinkable to your transaction log then you can ignore mixing your coins. But some people load coins is a fashion that's linkable to their ID and they need to protect themselves by blinding their own transaction log.

QTC, could you elaborate? How would one loan their coins in a way that was linkable to their ID?
Title: Re: Anonymizing Bitcoins
Post by: Oldtoker on March 23, 2012, 07:30 am
Some people use Dwolla or another service to upload their cash from their Bank.  This links Dwolla to their Bank Account.  They then use BitInstant to transfer cash from Dwolla to Mt.Gox or another exchange service to purchase their BTC.  This links their BTC to their Bitcoins.  They then need to move their Bitcoins to SR through a Mixing Service so that the coins are not linked from Mt.Gox to SR.
Title: Re: Anonymizing Bitcoins
Post by: kmfkewm on March 23, 2012, 08:18 am
There are two primary ways to anonymize your bitcoins:

1. Obtain them anonymously. If the method you use to get bitcoins can not be linked back to you, then your bitcoins are anonymous. In short, bitcoins are as anonymous as the method used to obtain them.

methods of anonymously obtaining bitcoins:

A. Sell drugs for bitcoins
B. Buy with western union, using fake ID if required (semi-anonymous)
C. Buy with cash in the mail
D. Buy with moneypak (semi anonymous)

etc


2. Use a mixing service. These unlink your coins from your account. In short

Account (1,2) ----> Mix -----> Account(3,4)

Assume two people are using the mix. Someone watching the block chain can not link coins leaving the mix to accounts 3,4 to either accounts 1 or 2, because the coin from account 1 could have gone to either 3 or 4 and the same goes for account 2 (assuming that they both send equal amounts in and out). If a blind mixing service is used, even the mix itself can not link the accounts together. Get enough people using a mixing service and the outgoing coins have an equal chance of having originated at a huge number of people. Now when account 4 sends coins to LEs account 5, once LE trace the coins path back to the mix they can not determine if the coin actually originated from account 1 or account 2.

The best bet is to combine both of these techniques, because although both are anonymous they result in different properties. Obtaining coins anonymously can still be traced back to the cash in point in many cases (WU, whatever) and you then need to rely on the attacker not being able to link your identity to that cash in point. Using a mixing service anonymizes your coins after they exit the mix, but it doesn't hide that your identity used bitcoin + a mixing service. By layering both techniques together, you can hide the fact that you use bitcoin, hide the fact that you use mixes (potentially important to do) and hide the cash in location/technique that you used.

Title: Re: Anonymizing Bitcoins
Post by: SuperDimitri on March 23, 2012, 12:48 pm
A friend of  mine is considering selling them locally for cash. Of course, this would only work in our area, but that is another way to obtain them anonymously. Check your local craigslist! Just make sure you ALREADY have a wallet, no one likes waiting around for you to set one up!
Title: Re: Anonymizing Bitcoins
Post by: Gigles on March 23, 2012, 06:33 pm
How bad of a vulnerability is it to have already sent bitcoins from MTgox directly to SR?..
Title: Re: Anonymizing Bitcoins
Post by: marv on March 24, 2012, 12:49 am
A friend of  mine is considering selling them locally for cash. Of course, this would only work in our area, but that is another way to obtain them anonymously. Check your local craigslist! Just make sure you ALREADY have a wallet, no one likes waiting around for you to set one up!

Does the SR account count as a 'wallet' or must there exist a wallet separate of SR?

Gigles, that's a good question. I am wondering if I need to go through all the heavy steps if I will just order a few small things, once in a while, from SR.
Title: Re: Anonymizing Bitcoins
Post by: raven92 on March 24, 2012, 04:28 am
A friend of  mine is considering selling them locally for cash. Of course, this would only work in our area, but that is another way to obtain them anonymously. Check your local craigslist! Just make sure you ALREADY have a wallet, no one likes waiting around for you to set one up!

Does the SR account count as a 'wallet' or must there exist a wallet separate of SR?

Gigles, that's a good question. I am wondering if I need to go through all the heavy steps if I will just order a few small things, once in a while, from SR.

SR accounts have a wallet, you can go right from MTGox / GetBitCoin to SR.

Do you need to go through, MTGox logs everything you do, which has your IP. If you access MTGox via TOR you'll likely be needing to provide them with ID or you're money will be frozen. Now your IP only really matters if you get in trouble, or LE is SR / busts SR.

Given the above, its kind of like insurance/security, maybe an extra 35% sure you wont spend the next 5 years of your life rotting in a prison cell for $30 on $1000...
Title: Re: Anonymizing Bitcoins
Post by: QTC on March 24, 2012, 03:03 pm
well mixes take more like 1-3% but this of course further reinforces your point
Title: Re: Anonymizing Bitcoins
Post by: pholscolloid89 on March 24, 2012, 11:11 pm
How bad of a vulnerability is it to have already sent bitcoins from MTgox directly to SR?..

Also interested. I only buy small quantities for personal use, spending about 20BTC at a time max.
I do nothing to protect myself whatsoever. I transfer directly from my bank account to mtgox, and then directly to SR.
Should I worry?
Title: Re: Anonymizing Bitcoins
Post by: vlad1m1r on March 24, 2012, 11:22 pm
I'm about to receive some Bitcoins for the first time for providing an item - I am toying with the idea of simply giving the id of my account on Bitcoin Fog, then slowly transferring it to my personal wallet (on USB stick) before finally transferring it to another BTC provider who can wire the funds to my account - I imagine this is fairly safe? Any thoughts anyone?

V.
Title: Re: Anonymizing Bitcoins
Post by: doorsofperception on April 12, 2012, 05:34 am
I do the same thing. Buy my coins and deposit straight to SR. Does this make us vulnerable?

How bad of a vulnerability is it to have already sent bitcoins from MTgox directly to SR?..

Also interested. I only buy small quantities for personal use, spending about 20BTC at a time max.
I do nothing to protect myself whatsoever. I transfer directly from my bank account to mtgox, and then directly to SR.
Should I worry?
Title: Re: Anonymizing Bitcoins
Post by: doorsofperception on April 12, 2012, 07:19 am
would you recommend using Bitcoinfog?
Title: Re: Anonymizing Bitcoins
Post by: vlad1m1r on April 12, 2012, 06:23 pm
would you recommend using Bitcoinfog?

Bitcoinfog is my mixer of choice. Their commission is 1 - 3 % which is randomised for your safety. There are options to withdraw your funds automatically in small amounts at random intervals, the longer you take to withdraw your funds, the greater the level of protection.

See also:

http://bitcoin.stackexchange.com/questions/52/how-anonymous-are-bitcoin-transactions

V.