We've sent you a pm.

We've extend the deadline already but there are still some deposits left. Please withdraw ASAP.

Dear all, the current maintainers of blindmixer have decided to no longer continue.

Please withdraw your money from the current custodian before October 1 2023.

If you have issues, do not email, post them here.

Kind regards,

Have you taken a look at our service? I think we have implemented exactly this!

Please check your email, we should have responded now. Apologies.

For those curious, the transaction was never propagated due to a flaw in our fee selection, as it was somehow below the min relay fee. We hope to have fixed issue this now.



Well yes, but not quite: see, apart from browser headers and your ip, there is in theory nothing that connects your deposit to your withdrawals, as we use blind signatures in order to break that connection.
However, if you restore (resync) your wallet you will indeed make it very easy for us to infer what deposits and withdrawals belong to you, as you are querying them in quick succession.

This is a real problem we are not entirely sure how to tackle yet. Perhaps we could only allow you to restore your wallet at a certain time of day, so as to make it impossible for us (and cloudflare) to guess if there is just 1 individual restoring, or multiple.



Indeed, it is quite trivial to guess which input belongs to which output, and really boils down to simple probability, especially with a small set of active coins (unused blind signatures).
We acknowledge this. The only way to really overcome this is by growing our userbase. Yes, we could also impose additional restrictions such as not allowing you to withdraw random amounts, or forcing you to wait some time before withdrawing, but that would probably be detrimental to the UX.


We have thought about encrypting the data before sending it to our server and we might revisit this soon because indeed, there are not really any cons apart from the fact that it does not really improve your privacy, but rather gives you the illusion that it does since we can still see your ip and headers associated with an action and connect the dots.
There is really no way around it, to attain privacy you as the client will need to be proactive as well. Use the tor browser and rotate your IP between deposit and withdrawal. Wait a little bit before withdrawing, and don't withdraw the same, close, or division of the original amount.
 
You still might be misunderstanding what blindmixer offers: we don't know the inputs associated with your unblinded coins (though we can of course infer), not just as a promise, but as a fact.
As a result it can happen that you receive your own inputs back, because we do not associate them with "you"; that is, your original deposit. It would be impossible for us to do so due to our usage of blind signatures.

Everyone should want a mixer where this happens as a result of using blind signatures, because it is a symptom of providing true privacy, and not one that is merely based on promises.

We could indeed push the raw transaction hex to users, but it would not have helped in your case as the transaction was simply invalid.

Apologies again and agreed, there are still a lot of bugs we need to iron out and plenty of ways to improve the current product.

blindmixer might be a nice example of this: we already utilize blind schnorr signatures, and have full non-repudiation:

every action taken by the client requires a signature that only the client can generate, as such we cannot dupe any single user with it being proveable.

A consequence of this is that it is a little more complex than a single webpage: the client needs to actively generate signatures and store them. JS will be required. Still, we believe that we packaged it as simple as possible for the average user.

A huge drawback currently is that our scheme is centralized, meaning that we can exit-scam at any point. We have looked into using a MuSig scheme with multiple signers, and it should definitely be possible. Don't think it will play very nicely with lightning as of right now, but that will undoubtedly change in the future.

Bump! We have temporarily increased our deposit fees to 1%. We intend to use 100% of these funds to kickstart a signature campaign. Lightning deposits are still free.

Did you use the batch functionality by any chance?

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Let us know if you have any questions.

We are having issues with our provider of hosting. We are trying to solve this before migrating.

There is about 0.02BTC hooked in that we currently know of which includes the BTC from above poster.

Sorry for the inconvenience.

Resolved, sorry. Your transaction was stuck due to lack of initiating transactions.

We also think we offer something that might be of interest to users looking for alternatives to coinjoin:

 - blinded submarine swaps
 - reverse submarine swaps - though both of these are with counterparty risk
 - internal transfers,
 - regular blinded on-chain deposit/withdraws, against (currently) 0% fees - this might change at some point in the future
 - Economies of Scale

The privacy implications of our product are enormous and pretty revolutionary if used correctly: your withdrawn funds will be consisting of any deposit made by other users, including your own.

Given a large enough userbase and correct usage of our product (for example: timing & non-unique withdrawal amounts) we believe that a very high degree of on-chain privacy can be achieved.

Though of course there is (as of right now) a significant catch: we are a centralized entity. While all of our communications are provably-honest and privacy against us is retained using blinded schnorr signatures, we can at any point in time break that promise.

We think our product stacks up very well against currently existing mixers
 
 + free internal transfers - allows you to transfer btc to a friend off-chain / with privacy
 + complete lightning integration - make blinded lightning transfers
 + provably-honest communications
 + blinded-sig scheme - provable privacy against the mixer
 + cheaper - only pay network fees as of now
 + can be used as a day-to-day wallet - added privacy + no additional transactions required in comparison to traditional mixers
 + insert withdrawal as a batch transaction - only pay for the output space ~31 vb
 + open-source software
 - incorrect use or lack of use by other users can make it easy for blockchain heuristics.

compared to CoinJoins:

 + more flexible - withdraw any amount at any point
 +- may or may not offer better on-chain privacy. This is something that largely depends on how many users we have and how you use us*.
 - centralized - requires custody over your funds
 + cheaper ?
 + can be used as a day-to-day wallet - added privacy + no additional transactions required in comparison to traditional coinjoins


Looking forward to hearing you guys' opinions about us. Would you want to use us?

Thank you! We've added this to the list of bugs to fix.

Bump! Looking for people to test and review our software!

Bump! Looking for people to test and review our software!

Please note: the wallet has been updated!

New wallet file:

Updated Signature:

Get the signature:

^ Probably an easier way to do this

Wallet file:

Should check out!

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Let us know what you think!

Right! You can seamlessly switch between making an on-chain transaction and lightning. Make a deposit on-chain, withdraw using lightning!

Yes, this would be very possible even while largely retaining the current code of blindmixer. This is something we're interested in doing in the long-term, as it is currently the single biggest caveat of blindmixer! ...Though we're not quite sure yet how complicated this will become. 

Sorry for the lack of detail in my answer; I am intentionally keeping this a bit vague for now as it's a bit of an empty promise as of currently.

Please note: blindmixer already has this. We cannot link your in- and outputs like traditional mixers can, though we can obviously still log your ip and so forth.

Making the mixer decentralized would as I currently see it really only change the backend and besides decentralization not add much in terms of actual privacy related features... + We might actually have to scrap certain features like lightning completely.


I think in a multisig scheme such a thing would not necessarily be required - signers can agree to a predefined split and correspondingly dynamically sign transactions or blinded coins.

Bump!

Thank you for doing so, first of all.

Both of these issues are actually intended behaviour, though it can probably be repackaged to look a bit more professional.

I see. This is because you're asking the host (github) for a certain URL that only existed client-side (SPA). We should just automatically redirect you back to the "login page" to avoid any confusion.


This is also intended behaviour; the wallet is not really supposed to be "refreshed". If you have just made a transaction it should automatically redirect you to the transaction status. Refreshing the transaction page will not actually fetch any new data. Perhaps it does display previously unseen states that were already stored locally but not visible yet, however switching between the send/receive/transaction tab should make these new entries visible -- there would be no need to refresh. I guess this should perhaps be made more clear?

The "check" button sends a request to a blockchain explorer to discover if there have been any new transactions made to said address - if so - the wallet will ask the custodian to accredit the deposit.
I agree with you that there are two potential issues / improvements. We could remove the button on the /receive/ tab and automatically check the latest address to see if it received any new deposits, (but keep it on /addresses/ as that would become resource-intensive)

And secondly we should probably redirect users to the deposit once it is found. Currently after clicking "Check" you should switch back to the transactions tab to see the new transaction item and the corresponding information, which is admittedly a bit confusing. (No page refresh is needed though)

The sync button checks for any missing deposits, withdrawals, or unfinished states (unclaimed) by querying the custodian with your deposit addresses + unspent coins. You can try and see for yourself by taking your current seed, restore, and click sync. The transactions tab should automatically be populated with all of your previous transactions, and attempt to finalize them.

We support sending to Taproot addresses starting with witness version (1). I'm not sure what current developments are (if there have been more witness versions introduced) We don't support generating taproot deposit addresses, not until bitcoin core supports it anyway.

double click the input field and the url for the testnet custodian should show up (https://testnet.blindmixer.com/#pubmp1qf98kxatpw43mqjft6j72dps5wn66yzp47k3zm0yn4skhedv32x5sphklj2)

After that, simply deposit using a lightning testnet wallet or a testnet faucet.

Correct. Since the wallet is fully custodial it can only be restored with your current custodian.

This was done to reemphasize the importance of remembering the right custodian in case there would have been multiple operators running the blindmixer software, which has not been the case thus far. Still, you might get confused between testnet and mainnet wallets.

Hi everyone! We're looking for your feedback!

If you wish to review our service and let us know what we could improve on feel free to comment.


An update on this:
We're not sure what changed but our wallet now works by default if you use the standard tor browser settings.

If you use the tor browser in combination with something like Tails (4.28) you still need to go to

As the title suggests we are looking for feedback and things to improve.

If you wish to review our service, please do so by all means.
We will respond to all of your comments and categorize the given feedback if we can confirm the issue, and keep you updated as to whether or not it is fixed.

Current feedback:

Example:
 - Add XYZ (suggested by XYZ) Status: XYZ

Bugs:
 
 -

Features:

 -

Improvements:

 -