Quote from: teairrrra on October 12, 2017, 11:23:44 AM

Imagine I want to consecutively mix some bitcoins. I mix 1 BTC, then after a week another 2 BTC.
How can I be sure that the 2nd time I won't receive my own bitcoin from 1st mix?

You can't be sure about that, but it doesn't really matter. I've asked a similar question before, this was the response:

Quote from: ChipMixer on July 26, 2017, 12:28:55 PM

There is no guarantee, there is chance and receipt. Chance means that if you send 1 BTC out of 100 BTC pool, you have 1/100 chance to receive the same coins. Even if you would receive the same, there would be no proof they are the same. It is like throwing a dollar into cup of dollars. Even if you pick the same one, they are fungible and there is no difference whenever you pick any of them. Receipt is a signed proof you have received funds from ChipMixer.

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bitmixer.io had "codes" that would tell them not to mix my previous bitcoins with following.

Or so they said, but they also said to delete all data. Read this comment in their thread about it:

Quote from: Gleb Gamow on July 02, 2017, 03:12:10 PM

https://bitmixer.io/faqs.html

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What is a Bitmixer code?

After your first exchange you will receive a special Bitmixer code. This code makes sure that you will never receive any of the previous coins you have added to our reserves in any subsequent transactions you make with Bitmixer. In other words this ensures that you remain untraceable.

Day 1: I mixed U$100 worth of bitcoins and received a Bitmixer code so that when I mix subsequent coins I won't received what I previously mixed back. Fine!

48 Hours Later: I mixed another U$100 worth of bitcoins and received bitcoins back which none were of what I've mixed two days prior. Fine!

36 Hours Later: I mixed another U$100 worth of bitcoins and received bitcoins back which none were of what I've mixed two transactions prior. Fine!

Question: How were the last two transactions achieved given the following? ...

http://themerkle.com/news/interview-with-the-owner-of-bitmixer-io-a-high-volume-bitcoin-mixer/

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Our servers are located in a country where US authorities cant get access to the server without a local court order. Bitcoin is not considered as money here, so we cant be a money-laundering service. We use encrypted disks. We delete all order data after 24 hours. We completely erase old bitcoin addresses from our wallet after coins are sent out. Even if the server is seized, they will find nothing.

Clearly, my Bitmixer code remains on file attached to bitcoin wallet addresses I've previously used, else there would be a strong possibility of me receiving some of the coins back that I may not want attached to me, but that would be an impossibility given that ALL order data is purged from your system within 24 hours, as stated above, resulting in the 3-LAs et al. finding nothing.

Further, I'll be paying you a fee to mix coins stemming from a nefarious act with the strong possibility that I'll be receiving coins stemming from a nefarious act tens of times worst than what I'm tryin' to hide. Surely, wouldn't that bring the feds to my door a knockin' a helluva lot quicker? It'll be pretty embarrassing for me to defend myself if accused of running a underage goat brothel when in fact I ONLY pimp out adult chickens and occasionally a matured goose (soon to pimp ducks - drakes and hens).

Humor aside, I look forward to your reply, devs.

Bruno

Three weeks after this comment, BitMixer closed.