What is the mixing fee?
fix fee never more than 1% btc for all mixing but not less than 0.0001 btc
How many output addresses can I specify?
Between 1 and 5.
What is the minimum amount I can mix?
0.0025 btc multiplied by the number of output addresses you specify.
So if you enter 3 output addresses, the minimum is 0.0075 btc.
What is the maximum I can mix at once?
0.1 btc. We hope to raise this in the future as the site gets more users.
How long do I have to send in my payment?
24 hours.
How soon will I get it back?
If you choose "fast" then within about an hour.
If you choose "slow" then within about 4 hours.
If you specify more than one output address, your payment will be
sent to you in separate transactions for each output address,
with additional delays between each payment.
What happens if I don't follow the rules?
You'll lose your bitcoins.
If you send in less than the minimum, then you'll get
nothing back. If you send in more than the maximum, then you'll only get the
maximum back. If you send in bitcoins after the deadline, then you'll get
nothing back.
How long do you keep logs of mixing transactions?
Logs are kept for 3 days so that we'll be able to help users who have
problems or questions after their mix is done. After that all records
are deleted.
What is a bitcoin mixer?
A bitcoin mixer is a tool that lets you trade your bitcoins for an equal
amount of someone else's bitcoins (minus mixing fees).
Why would you use a bitcoin mixer?
In order to spend bitcoins more anonymously. If you have bitcoins you
purchased non-anonymously (like through a bank transfer) then you can use
a mixer to trade your coins for someone else's coins. Now you have coins
that are not tied to your identity and thus your purchases with these coins
are more anonymous.
How does a bitcoin mixer work?
First, you tell the bitcoin mixer the wallet address(es) you want your
coins sent to. Then the mixer
tells you which mixer wallet address you should send your bitcoins to in order
to have different bitcoins sent back to you. You send in your coins
and after a certain delay you get back the same amount of someone else's
coins (minus mixing fees).
Can you give me an example of how it works?
Let's say Alice has 0.5 btc in her public wallet address x123 and wants it
transferred to
her secret wallet address x898. Bob has 0.5 btc in
his public wallet address x456 and wants it sent to his secret wallet address
x767. Alice puts x898
into the mixer
and it tells her to send her bitcoins into mixer address x333. Bob puts x767
into the same mixer and it tells him to send his bitcoins
into mixer address x444. Alice sends in her bitcoins and gets back Bob's
bitcoins. Bob sends in his bitcoins and gets back Alice's bitcoins. Now,
when Alice and Bob spend their bitcoins, they are not spending the coins
they originally purchased.
In the example below, Alice wants to buy bitcoins with a bank transfer and
then transfer them into her web wallet at a secret market where she has the
name cat_lady. Bob also wants
to buy bitcoins with a bank transfer and transfer them into his web wallet
at a different secret market where he has the name dog_man.
This is the path of the bitcoins:
As you can see, it appears that Alice's bitcoins are spent by
dog_man and Bob's coins are spent by cat_lady.
But what if the person Alice exchanges coins with buys something bad?
Can Alice get in trouble?
Probably not, because whoever might accuse Alice of making Bob's purchases
would likely need some kind of evidence tying Alice to those goods or
services. It's unlikely Alice would be punished simply because the bitcoins
she sent into a mixer were eventually used for something bad.
As a real-world example, let's say someone was accused of being a bank robber
because he tried to purchase something
with dye-stained money. His usage of dye-stained money alone does not prove
his guilt, as he might have acquired that money as change at a convenience
store that was frequented earlier by the real bank robber. More proof would
be needed, such as witness statements or physical evidence left at the scene.
So by using a mixer you in effect trade your bitcoins' history and future
path with those of another person. Thus any linkage to past or future
misuse of those bitcoins is swapped. This increases the plausible deniability
that any specific person is tied to any specific misuse of these bitcoins.
This all sounds so shady.
Privacy does not necessarily imply shadiness.
What are the holes in this plan?
First, you have to trust the mixer to keep the relationship of originating and
outgoing bitcoin addresses private. Otherwise, there is no point to mixing.
Second, even though there is no a direct blockchain link between Alice's
non-anonymous original bitcoin address and her anonymous destination bitcoin
address, data analysis of the blockchain could uncover likely connections.
For example, a dumb mixer might immediately send Alice her mixed coins minus
a consistent fee. Someone analyzing the blockchain might see 0.5 bitcoins
going x123 -> x333 and 0.49 bitcoins going x444 -> x898 a second later and
make a guess that x123 and x898 have a relationship.
What can mixers do to prevent blockchain analysis?
First, good mixers should randomize the mixing fee so as not to create
consistent numeric relationships between payments. Second, good mixers should
implement a randomized payout delay to increase the uncertainty about
related transactions. Third, good mixers should allow the user to split the
payout up among several addresses. That way someone analyzing the blockchain
could not match transactions based on similar amounts, but would rather
have to sum up several transactions and find transactions matching that sum.
But with enough time and effort, couldn't someone overcome these
methods of obfuscation?
Yes, but the analysis would produce educated guesses, not proof. If
Alice is known to control address x123 and sends coins directly from
x123 to address
x898 then one can say Alice has some relationship to x898 (either
it's her address, or an address she has chosen to send the coins to).
However, if she uses a mixer to send 0.5 btc to address x333
and 23 minutes later 0.49213 btc is sent
from address x444 to address x898 then one might guess, based on the similar
payment amounts, that the transactions are related. But it can't be proven
based on this alone. Thus, mixing provides some reasonable doubt to outside
observers trying to figure out how a specific person is spending his or
her bitcoins.
