Thank you very much Campaign Manager Hhampuz!

Everyone should have been paid and Hhampuz sent me the remaining coins.

Bitcoin Blender is shutting down. Please withdraw.

There where some issues today but they have been solved now, apologies for the delays.

The thesis is from December 2017, I read it a long time ago and it does not mention Bitcoin Blender, they attack Coinmixer.se, not Bitcoin Blender.

The attack it describes requires that the mixer publicly publishes statistics on how many mixer transactions they have done over the last week (which I don't)
"In all mentioned attacking scenarios, we assume that the attacker is able to retrieve publicly accessible statistics which may be published through the centralized mixing service."

It then mentions some other flaws of Coinmixer.se necessary to identify their transactions, the most important was that they used a static transaction fee for all withdraws, on Bitcoin Blender each withdraw sent have a randomized transaction fee.

Coinmixer.se also always set a locktime of the current block on their transactions, on Bitcoin Blender it is randomized if locktime is set on transactions or not.
Further Bitcoin Blender also randomizes if RBF is to be set on the transactions sent.

Yes it was an expired SSL certificate, the autorenew with Lets Encrypt did not work.

In this case, for registered accounts there is a "Proof of Ownership" on the deposit page, a PGP signed message which purpose is so users can validate it and be sure the deposit addresses in the message was generated by me and they are not on a phishing site.

The "Bitcoin Blender Guarantee" you talk about is given on the Quickmix page, it contains both deposit address and destination addresses, so it is a much better proof to have in case I don't deliver the coins to its destination.

You can now withdraw bitcoin using Lightning by entering a lightning invoice on the withdraw page.

I check the support messages on the site a few times per day.

I know I don't sign in on Bitcointalk often but I do check this thread for activity regularly.


Thank you

If someone where to try and follow your coins, they see you move 100 BTC and suspect you put it in a mixer. They would then not be able to follow those coins to find out where you withdrew it, they would need to go check all bitcoin transactions and see if they find a transaction of 97-99 BTC in a block after the transaction. 97-99 is within the 1-3% service fee i take. Every hour there are approximately 10-15 000 transactions, some of them are between 97-99 BTC, after a day there should have been enough transactions on the bitcoin blockchain within that range that they cant know which one is yours or if you even withdrew yet or not. To make it harder for them to guess which transaction would be your withdraw its a good idea to withdraw to maybe 2 addresses and with randomized amounts and long randomized delays.

No

No I wont tell you, but it depends on the amount of coins in the mixer wallets and the volume users make. Higher volume (deposits/withdraws) and a lower amount of coins in the mixer wallets would make the coins move faster, stay shorter time.

No. The minimum amount is 0.001 BTC right now, the information about minimum amount is on the quickmix page and the withdraw page if you use registered account.

Can you point me to where it says that quick mix happens "four times a day"?
Quickmix creates your withdraw directly after your deposit is added to your balance, there is no delay except if you specify one when creating the quickmix.

As I explained in my previous post about this, the system does a taint analysis on all deposited coins to see if they have previously been on Bitcoin Blender to take care of this problem.

Correct, I have been thinking about making the taint analysis tool available on the site, as a way for users to verify that the new coins they received has no taint to the original coins but it would be better if it was provided by a third party instead of me. https://bitcointalk.org/index.php?topic=436467.msg46285715#msg46285715

Mixing 100000 BTC? It's going to take a long time. I suggest reading the Best-Practice Guide that is on the front page of the mixer, "Delay your withdraws" and "Withdraw to Multiple Addresses".

The clearnet site uses a different hosting provider, registered anonymously. There is nothing linking the clearnet site to the hosting provider used for the mixer.

Thank you for showing interest! Will try and answer as much as I can



I need backups to be sure I don't lose users coins, their current balance etc. The message you quote is old and things have changed since then. I take backups every minute now, and they are copied using rsync over Tor to a backup server that is kept as a copy of the original server. In case the original server hardware fails I can quickly change over to the backup server as its always ready. Both are bare metal and are installed by me (Not Windows) and uses full disk encryption. Old backups are of course also removed.

Old log files are removed. In the database old withdraws, deposits, deposit addresses, support messages, quickmixes, login attempts are removed. Nothing is saved. Each row in the DB is timestamped when added and then later removed. I like to keep the database as small and fast as possible.


When you open the withdraw page the mixer checks the coins currently in the withdraw wallet and if there is enough in there for you to withdraw your whole balance or not.
You either get a message that it is ready, or a message that it is not ready. Usually you never get the other message where it explains you have deposited too much because you would need to deposit around 800-900 BTC at once (i don't like keeping too much on hot wallets). That message explains that you can either wait for the mixer to catch up so you can withdraw or wait for me to move in coins from cold storage, and recommends the user to contact me through support.

I will change the message as it is misleading, of course you can withdraw less than your whole balance.

Deposited coins are sent and mixed in different ways on the way to the withdraw wallet and thats where withdraws are sent from. The system keeps track of the coins original owner and will never send coins originaly deposited by the same user.



Quickmix and automatic withdraw is not the same thing. Automatic withdraw is a feature registered users can choose to activate, the withdraws created by automatic withdraw have a forced randomized delay between 1-18 hours, it has a high randomized delay to prevent that. The problem with the automatic withdraw feature is that users set their addresses there once and then don't seem to change them often, so it encourages address re-use which is bad for anonymity.



Correct, the quickmix id is used instead of a username to keep track of your coins. So if you come back later and you enter the same quickmix id it wont send you any of your old coins on withdraw. If you don't mix more often than maybe once a week your old coins would have been sent out from the mixer by then anyways.



As long as a part of your coins are still in the mixer wallet I keep track of them, each UTXO is marked as belonging to a specific user or several users. Usually coins are only in the mixer for a few days so its not a big issue to keep track of them. That will prevent your example above from happening, if I understood you correct?

But there are other interesting things that can happen. Hope I can explain this so it makes sense with this example..
User A deposits 100 BTC to Address 1A. Some part of the coins deposited on 1A is eventually sent out of the mixer to another bitcoin service by some random Blender user.
User B also have an account on the same bitcoin service and decides to withdraw his coins to Bitcoin Blender and receives parts of the same coins the other user deposited on that service. Now there are coins in the mixer which has taint to Address 1A but is deposited by User B... The coins once deposited on Address 1A could of course be sent between several different bitcoin services before ending up on Bitcoin Blender again, but there could still be some small taint % to Address 1A there.

Thats why I have built my own taint analysis tool into the mixer, it is similar to the one blockchain.info used to have.

So on withdraw the mixer checks that the UTXO it is about to spend does not belong to you, and it also checks the taint on that UTXO. It checks that any of your deposit addresses is not in the taint report of that UTXO. Once you remove a deposit address it is kept for 7 days before the link to the user is completely removed, after that this taint check wont work for that address.

Yes it is still running, I know he had to be away for a while but he should be back at it again now.

That is not my website, check the URL in this announce thread.


That URL is to a scam/phishing site, check the URL in this announce thread.


bitblender5iclkw.onion is a MITM proxy to the real Bitcoin Blender site, any bitcoin addresses sent through their proxy will be replaced with theirs and they might hide some features like you mention the link to the Proof of Ownership PGP message.

There was a taint-analysis tool on blockchain.info that I used to recommend for checking this, but blockchain.info have removed that feature from their site.

I have built my own taint analysis tool but its just for my use because not sure why you would want to use my taint analysis tool to analyze the withdraws from my service, it would make more sense with a taint-analysis from a third party instead?

Yes the site mentioned in that thread is a scam/phishing look alike site, it is very unfortunate that people still end up on them. People need to be more careful.



All messages sent to me through support has recently been answered, please check.

Sorry but that is not the correct URL for Bitcoin Blender, it is http://bitblendervrfkzr.onion/

So you have Two Factor Authentication activated on your account, if the text box where the encrypted message with the One Time Password should be is empty it is probably because the PGP key is expired.

Register new account and talk with me through support.

Register account on correct URL, add a PGP key. Remember the correct URL.

Mixing slowly is the best way: Deposit 50 BTC spread out over your 5 deposit addresses, then create withdraws to maybe 8 addresses with randomized delays, 2-12 hours for example. Login again after 12 hours, remove your old deposit addresses and create new ones, deposit, create new withdraws. Repeat for a few months until you are done.

You can read a guide here https://bitblender.io/guide.html it explains why using multiple destinations on withdraws, randomized fees on the mixer and randomized delays on withdraws are important.

The URL in the first post in this thread is correct, the same URL is in the signature of all my posts.
You can also verify that the Proof of Ownership PGP message (found on the deposit page) is correctly signed by my PGP key.

Once you have registered you can add a PGP key to activate 2 Factor Authentication.

New deposit addresses will be segwit (P2SH).
Support sending/withdrawing to Bech32 addresses.

That is correct!

Users now have to pay for the cost of transactions on Blender because the 1-3% randomized service fee is not enough to cover the costs of bitcoin transactions when users want to mix only 0.01 BTC or even less.

The new fee system explained in my post above have now been activated.
The information have been displayed on the website for 4 days before activating the new fee.