 How do mixing services work? Do they put dozens of inputs and outputs into each transaction... in order to circulate the funds while incurring minimal transaction fees? Yes, Pablo. What you're describing there is called a coin join, which was invented by, I think, a couple of people... but most prominently, Greg Maxwell, who's one of the Bitcoin Core developers back in 2012 or 2013. A coin join transaction is one where, over several rounds with several transactions, the inputs and outputs... are shuffled and joined from several different participants, where each participant partially signs their input... and their output in such a way that the transaction can proceed in a way that they don't have to trust the other participants. By mixing inputs and outputs across several rounds of transactions, perhaps four, six, eight, or ten transactions... these types of services, which do coin join, offer the ability for people to reduce the ability of analytics... companies and snoops and other privacy violations, then not foolproof. Pablo also asks, are there any mixing services that can really make funds anonymous, given the growth of analytical tools? The answer, Pablo, is really no. The reason for that is because, while these services can obfuscate transactions... for the purposes of just relative privacy, given sufficient analysis, and also these analytical companies... have access to information from exchanges that identifies addresses and associates it with specific people, the combination of having a broad picture from multiple exchanges and merchant services that are feeding them data, and the ability to do statistical analysis, means that most of that anonymity can be stripped away by analytical tools. Part of the reason for that is that, while addresses can be made stealth and the identity link made weak, in a coin join transaction, the one thing you can't hide is the value. You can do statistical correlation analysis on the inputs and outputs to associate the values as they're going through. The values are shown clearly within a transaction. The solution to that also comes from Greg Maxwell, who has proposed and implemented a prototype of a system... called Confidential Transactions, which is a system that encrypts the amount in a transaction, but still allows everyone to verify that the amounts add up without knowing what they are. Confidential Transactions is something that has been part of the Elements project at Blockstream. It's developed quite a bit. As part of Confidential Transactions, Greg Maxwell invented some new cryptography, including range-proofs, which then became more and more efficient. The latest version of range-proofs is called bullet-proofs, which is a very efficient mechanism... for proving that the values add up even though they're encrypted within a Confidential Transaction. Confidential Transactions encrypt the value, but that doesn't mean they're used on their own. They would be used in conjunction with something like coin join to mix up the addresses. If you have both address anonymization and the encryption of the amount, then analytical tools will have a very difficult time tracking transactions. The final question from Pavelol in the same theme, is it cheaper and more effective to anonymize funds by exchanging them into Monero and BAC? Possibly. There are some significant risks in doing that, in terms of privacy and anonymity. Most of the time, exchanging funds, at least through a third party, such as an exchange or shape-shift, will produce a trail, because those companies, for many different reasons, have to collect some information. That information may be captured, let's say, by various parties. What's more interesting is the possibility of doing atomic on blockchain swaps between cryptocurrencies... as a means of increasing anonymity and privacy, including atomic cross-chain swaps through payment channels on lightning network. That may have a significant impact on privacy and anonymity in the near future. These are still pretty early days when it comes to privacy. As I've said, I think this is one of the weaknesses of almost all cryptocurrencies. Vikas asks, can Coinjoin and Tor be used to offer a level of privacy on the Bitcoin network? Which wallet currently offers these services? Does Coinjoin require you to trust the third party for the transaction? Vikas, yes. Coinjoin and Tor are tools that are often used to increase the privacy you get on the Bitcoin network. I know at least one wallet that offers both Coinjoin services, they call them Ricochet, but it's basically the same type of coin mixing and redirection, and also offers Tor networking. That's Samurai Wallet. I believe you can also configure other wallets, like Mycelium, I believe, Brett Wallet, and a few others. You can configure them to use a Tor transport. Finally, does Coinjoin require you to trust a third party for the transaction? No, it doesn't. It's a trustless multi-party signature protocol.