Mixing Bitcoin twice in series in case your mixer is a bad actor or mixes poorly

[sega01]

Update: This is now available in your browser. Double Bitcoin Mixer http://doublemixwcfx4wadeuvuygpxej5jpu7uleesh3yptopnbj5kshnlrid.onion/



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Use of any one mixer comes down to trust. Trust that the mixing is sound, that the mixer is not compromised, and that it's not a honeypot to begin with.

Using two chained mixers mitigates most of this risk. Odds of having two bad mixers is far lower than just one.

To this end, I've written a Python 3 library and CLI for Privcoin, Foxcoin, and Bitmix. They can be used separately, like

Code:

pip3 install privcoin; privcoin mix --currency bitcoin --output_address 1aaaa...

,

Code:

pip3 install foxcoin; foxcoin mix --currency bitcoin --output_address 1aaaa...

, etc.

The improvement is using two mixers, together.

Code:

pip3 install doublemixer

Code:

doublemixer mix --currency bitcoin --output_address 1aaaa...

You may wish to run it with torsocks to route the traffic over Tor.

This is completely client side, so no need to trust a third party. Just be sure to review the code of privcoin-python, bitmix-python, and doublemixer-python before use. Absolutely no warranties expressed or implied, no liability on the author's behalf, etc.

Source code for doublemixer on Github

In action:



I can also make a browser (still 100% client side) version of this, both clearnet and a .onion if there's interest.

[sega01]

Use of any one mixer comes down to trust. Trust that the mixing is sound, that the mixer is not compromised, and that it's not a honeypot to begin with.

Using two chained mixers mitigates most of this risk.

Let's say there are six mixers.
And one of the mixers is a parrot.
Now the odds of hitting one that is a parrot goes up the more mixers you use.

A better way to try to convince people to use a mixer, is to show with analysis that multiple mixings or mixers show greater [whatever desired reason for a mixing to start with].

If one of the six mixers is a parrot, it doesn't matter. It ony knows that it's mixing coins for one part. Could be mixing a mixer's output and sending to a mixer's input, know your source address, or you destination address. All mixers would have to be linked parrots for there to be an issue.

Mixer analysis has already been done on most of the individual mixers. If either mixer gives a good mix, there should be no taint. The mixer knows your source and destination, if you only use one and it's compromised, there's an established link between your coins that the parrot mixer knows about.

If you were randomly using different mixers in parallel, it would be much worse than a single mixer. Series is where there is the advantage.

[AndreyVen]

Very nice work, thank you for sharing!

Mixers are becoming increasingly more popular these days... Geehh I wonder why.

[Quickseller]

I would advise against doing this.

Both mixing services are only guaranteeing the address will be valid for a limited amount of time. If there is a problem/delay with the 1st mixing service that causes the transaction to confirm after the cutoff time for the 2nd mixing service, or if multiple transactions are sent from the first mixing service with the last one being after the cutoff, then the second mixing service may not send you your money. This would be a real problem because some mixing services periodically delete their private keys associated with zero balance addresses in order to protect privacy of their users in case a government agency finds their servers.

[Kristinnspence]

Use of any one mixer comes down to trust. Trust that the mixing is sound, that the mixer is not compromised, and that it's not a honeypot to begin with.

Using two chained mixers mitigates most of this risk. Odds of having two bad mixers is far lower than just one.

To this end, I've written a Python 3 library and CLI for Privcoin, Foxcoin, and Bitmix. They can be used separately, like

Code:

pip3 install privcoin; privcoin mix --currency bitcoin --output_address 1aaaa...

,

Code:

pip3 install foxcoin; foxcoin mix --currency bitcoin --output_address 1aaaa...

, etc.

The improvement is using two mixers, together.

Code:

pip3 install doublemixer

Code:

doublemixer mix --currency bitcoin --output_address 1aaaa...

You may wish to run it with torsocks to route the traffic over Tor.

This is completely client side, so no need to trust a third party. Just be sure to review the code of privcoin-python, bitmix-python, and doublemixer-python before use. Absolutely no warranties expressed or implied, no liability on the author's behalf, etc.

Source code for doublemixer on Github

In action:



I can also make a browser (still 100% client side) version of this, both clearnet and a .onion if there's interest.

That's pretty smart, but if you are using both mixers then don't you have to pay the fees on each one separately ? so fees will rack up?

[TryNinja]

That's pretty smart, but if you are using both mixers then don't you have to pay the fees on each one separately ? so fees will rack up?

Yes. In the example of the picture: 2,5% + 0,0007 BTC + 2,6% + 0.0005 BTC in fees.

If you mix 1 BTC with those settings, you receive 0,9498318 BTC.

Maybe you could add an option to calculate the total fees (and how much you will receive for what you send) when using both mixers.

[Kristinnspence]

That's pretty smart, but if you are using both mixers then don't you have to pay the fees on each one separately ? so fees will rack up?

Yes. In the example of the picture: 2,5% + 0,0007 BTC + 2,6% + 0.0005 BTC in fees.

If you mix 1 BTC with those settings, you receive 0,9498318 BTC.

Maybe you could add an option to calculate the total fees (and how much you will receive for what you send) when using both mixers.

Or even do outreach to the mixers and ask them for a collab and lower mixer rates or a piece of the cake at least and market the software as the holy grail of mixing and make a sweet looking GUI with flashy graphics, then say all this fancy stuff with two times more anonymity than any other mixer out there and almost untraceable transactions blabla

or make the software with a GUI and have all the mixing do in the background just put input/output address and a juicy looking loading bar with a funny message or something but just sell it for a small amount of money and license lock it

even you could
build the whole project on blockchain so that all the input&output addresses are unchangeable and can't get changed or hacked get it crowdfunded through an IEO as the new revolutionary mixer with huge anonymity and low fees

profit

thank me when u become a millionaire

[Wind_FURY]

OP, what if I had Wasabi Wallet installed on two computers, and I send some Bitcoins to one wallet, mix them, then send them to the other wallet, mix them, then send them back to the first wallet and mix them again?

https://www.wasabiwallet.io/

There's also no risk of losing custody of your coins, or risk of honeypots.

[PrimeNumber7]

OP, what if I had Wasabi Wallet installed on two computers, and I send some Bitcoins to one wallet, mix them, then send them to the other wallet, mix them, then send them back to the first wallet and mix them again?

https://www.wasabiwallet.io/

There's also no risk of losing custody of your coins, or risk of honeypots.

Wasabi always aims for an anonymity set of 50 when mixing. <> If you cascade transactions as I suggest above, then this multiplies, so after two transactions you have an anonymity set of 11*11=121,

Wasabi uses CoinJoin which can in theory be de-anonymized, depending on the specific input/output sizes. The more times you "mix" your coins with Wasabi, the more difficult it will be to trace your coins.

[buwaytress]

Or even do outreach to the mixers and ask them for a collab and lower mixer rates or a piece of the cake at least and market the software as the holy grail of mixing and make a sweet looking GUI with flashy graphics, then say all this fancy stuff with two times more anonymity than any other mixer out there and almost untraceable transactions blabla

But if the whole point of this exercise is to minimise exposure to a possible bad actor or poor mixer, then outreach and collab isn't just asking the enemy to sleep with you, but tainting the whole jar of milk, no?

Of course, as OP points out, using a mixer is all based on trust, after all. So I suppose if you could mark all the mixers you trust as safe for co-mixing in one melting pot, it does sound like something different.

In a practical sense, I'm sure a lot of people already achieve that... mixing, passing coins through exchanges, casinos, trading P2P...

[suzanne5223]

OP, what if I had Wasabi Wallet installed on two computers, and I send some Bitcoins to one wallet, mix them, then send them to the other wallet, mix them, then send them back to the first wallet and mix them again?

https://www.wasabiwallet.io/

There's also no risk of losing custody of your coins, or risk of honeypots.

Wasabi always aims for an anonymity set of 50 when mixing. <> If you cascade transactions as I suggest above, then this multiplies, so after two transactions you have an anonymity set of 11*11=121,

Wasabi uses CoinJoin which can in theory be de-anonymized, depending on the specific input/output sizes. The more times you "mix" your coins with Wasabi, the more difficult it will be to trace your coins.

You make a good point but the combination of all MIT license anonymity wallet(electrum,wasabi) with the use of 2 tumbler companies should be okay for I dont dont support making use of Wasabi wallet only that's not guarantee ones anonymity is sure remember.

there are several known weaknesses with Tor. You should always operate with the expectation that any anonymity system you use will eventually fail you. If you're ever confident in your anonymity, then you're wrong.

[yegor256]

Would also be great if you turn this into a web service.

But the question of trust will show up again...

[rmilly]

I would be really skeptical to use any mixers now. Two of the biggest have been shut down recently which I think are major red flags imo 

[naska21]

snip

[AdolfinWolf]

snip

Wouldn't it better to send bitcoins through out  the chain of  say five-six exchanges (where you have anonymous accounts) , return them back   into wallet and then we're there? Each exchange would act as a kind of  mixer in this case.

Could you name 5-6 anonymous exchanges? The only one i can think of is binance (which does chain analysis, so you'll need to find some more exchanges to effectively mix your coins), and yobit, which i find particularily untrustworthy.

Another problem is that most of these exchanges usually ask for .5 or 1% withdrawal fee. multiple that by 5x, or 6x, and you'll be paying massive amounts of fee for what might be just very little improvements in privacy.

[naska21]

snip

Wouldn't it better to send bitcoins through out  the chain of  say five-six exchanges (where you have anonymous accounts) , return them back   into wallet and then we're there? Each exchange would act as a kind of  mixer in this case.

Could you name 5-6 anonymous exchanges? The only one i can think of is binance (which does chain analysis, so you'll need to find some more exchanges to effectively mix your coins), and yobit, which i find particularily untrustworthy.

Another problem is that most of these exchanges usually ask for .5 or 1% withdrawal fee. multiple that by 5x, or 6x, and you'll be paying massive amounts of fee for what might be just very little improvements in privacy.

[AdolfinWolf]

snip

Wouldn't it better to send bitcoins through out  the chain of  say five-six exchanges (where you have anonymous accounts) , return them back   into wallet and then we're there? Each exchange would act as a kind of  mixer in this case.

Could you name 5-6 anonymous exchanges? The only one i can think of is binance (which does chain analysis, so you'll need to find some more exchanges to effectively mix your coins), and yobit, which i find particularily untrustworthy.

Another problem is that most of these exchanges usually ask for .5 or 1% withdrawal fee. multiple that by 5x, or 6x, and you'll be paying massive amounts of fee for what might be just very little improvements in privacy.

Will exchange #1  send  to exch #2 the same bitcoins that were received from me? I don't think so, IMO, they will differ from mine,  every next exchange belonging to my chain will continue in that, or am I wrong on that?

Agree, that  could impose extra costs compared with the mixers.

Well, they probably won't exchange/send the same bitcoin back to you, but that doesn't mean that they don't know the origin of the funds. Especially exchanges such Bitstamp, coinbase, and kraken all use third party chain analysis products, and probably share/won't hesitate to share that info with authorities/other exchanges.

Which means that, yes, the chain might look broken, but these exchanges can and will still keep track of the coins, especially if it's significant amounts not used for trading and send through regulated exchanges as mentioned above, and share that info to LE/other exchanges, which in turn will probably result to the funds being linked.


Hence why i don't think this is such a smart idea, apart from it costing a lot of $$$, and exchanges who probably won't be too happy about it.

[posi]

snip

Wouldn't it better to send bitcoins through out  the chain of  say five-six exchanges (where you have anonymous accounts) , return them back   into wallet and then we're there? Each exchange would act as a kind of  mixer in this case.

Could you name 5-6 anonymous exchanges? The only one i can think of is binance (which does chain analysis, so you'll need to find some more exchanges to effectively mix your coins), and yobit, which i find particularily untrustworthy.

Another problem is that most of these exchanges usually ask for .5 or 1% withdrawal fee. multiple that by 5x, or 6x, and you'll be paying massive amounts of fee for what might be just very little improvements in privacy.

Will exchange #1  send  to exch #2 the same bitcoins that were received from me? I don't think so, IMO, they will differ from mine,  every next exchange belonging to my chain will continue in that, or am I wrong on that?

Agree, that  could impose extra costs compared with the mixers.

Well, they probably won't exchange/send the same bitcoin back to you, but that doesn't mean that they don't know the origin of the funds. Especially exchanges such Bitstamp, coinbase, and kraken all use third party chain analysis products, and probably share/won't hesitate to share that info with authorities/other exchanges.

Which means that, yes, the chain might look broken, but these exchanges can and will still keep track of the coins, especially if it's significant amounts not used for trading and send through regulated exchanges as mentioned above, and share that info to LE/other exchanges, which in turn will probably result to the funds being linked.


Hence why i don't think this is such a smart idea, apart from it costing a lot of $$$, and exchanges who probably won't be too happy about it.

The above mentioned exchanges are definitely not good for someone who want to stay anonymous but I think the combination of Binance, bitshares, wasabi wallet should be enough strategy to stay anonymous since the exchanges and wallet are both good as anonymity is concern.

[Kakmakr]

This is not just a good strategy to reduce the chances of using a mixer that might be a bad actor, it is also a good strategy to reduce the chances that a single mixer service might have an exploit that are being tapped by authorities and that this mixer services are not even aware of the exploit.

I use the mixer service in my signature, because I have been using it for years without any problems and when I want to shift funds between my wallets and I want to obscure the link between them, then I use more than one mixer service. 

[Wind_FURY]

snip

Wouldn't it better to send bitcoins through out  the chain of  say five-six exchanges (where you have anonymous accounts) , return them back   into wallet and then we're there? Each exchange would act as a kind of  mixer in this case.

Could you name 5-6 anonymous exchanges? The only one i can think of is binance (which does chain analysis, so you'll need to find some more exchanges to effectively mix your coins), and yobit, which i find particularily untrustworthy.

Another problem is that most of these exchanges usually ask for .5 or 1% withdrawal fee. multiple that by 5x, or 6x, and you'll be paying massive amounts of fee for what might be just very little improvements in privacy.

Will exchange #1  send  to exch #2 the same bitcoins that were received from me? I don't think so, IMO, they will differ from mine,  every next exchange belonging to my chain will continue in that, or am I wrong on that?

Agree, that  could impose extra costs compared with the mixers.

Well, they probably won't exchange/send the same bitcoin back to you, but that doesn't mean that they don't know the origin of the funds. Especially exchanges such Bitstamp, coinbase, and kraken all use third party chain analysis products, and probably share/won't hesitate to share that info with authorities/other exchanges.

Which means that, yes, the chain might look broken, but these exchanges can and will still keep track of the coins, especially if it's significant amounts not used for trading and send through regulated exchanges as mentioned above, and share that info to LE/other exchanges, which in turn will probably result to the funds being linked.


Hence why i don't think this is such a smart idea, apart from it costing a lot of $$$, and exchanges who probably won't be too happy about it.

The above mentioned exchanges are definitely not good for someone who want to stay anonymous but I think the combination of Binance, bitshares, wasabi wallet should be enough strategy to stay anonymous since the exchanges and wallet are both good as anonymity is concern.

Any exchange > coinjoining in your Wasabi wallet > then sending your coins to your regular wallet, should be good enough for any regular user. Although, it's recommended NOT to share the same wallets with un-coinjoined coins.