Is Bitcoin anonymous? No. The ledger is public, and the name arrives later
Is Bitcoin anonymous? No. It is pseudonymous. Every transaction is public, traceable and stored for good, and a Bitcoin address is only a name until it touches a person: an exchange that asked for identification, an address you posted, a payment you reused. Bitcoin.org, the project's own privacy page, puts it the other way round from the slogan: Bitcoin is "probably the most transparent payment network in the world," and it "can provide acceptable levels of privacy when used correctly." CoinJoin and mixers change how hard that matching is. They do not make the ledger private. Operating a mixer that knowingly moved criminal proceeds is what sent Samourai Wallet's founders to prison in November 2025.
Pseudonymous, not anonymous
Chainalysis, writing in April 2022, uses the same distinction: nothing in a transaction ties it to a person except the address, a string that "functions as the user's pseudonym." Anonymous would mean the payment carried no handle. Bitcoin's handle is permanent. Once an address is used, bitcoin.org says, it is "tainted by the history of all transactions" it touches, and anyone can see the balance and every payment. The sting in that sentence is the tense. "Something not traceable currently may become trivial to trace in the future," because the chain does not forget.
The name arrives from outside the chain. "Users usually have to reveal their identity in order to receive services or goods," so the address cannot stay fully anonymous. An exchange that collected a passport, a shop that shipped to a street, a donation address printed on a website: any one of those is the join. After that join, the history of the address is the history of the person. The market seizures in the takedown record are full of this. The bitcoin was counted, clustered and taken. The anonymity was the address, and the address did not survive the exchange or the server.
How Bitcoin gets traced to a person
A confirmed transaction publishes more than people expect: the transaction id, the sending address, the receiving address, the change address, the amounts, and the time the block was confirmed. Chainalysis describes the time from sending to confirmation as 5 to 45 minutes. That pile of fields is public and, on its own, still not a name. The name is a second job.
Chainalysis's attribution, as that 2022 post describes it, has three stages. Clustering groups addresses the firm believes one entity controls, using co-spends, change addresses, behavioural patterns and peel chains. Identification attaches an entity to the cluster. Categorisation labels what kind of entity it is. This is a vendor describing its own product, and the post is four years old. The method is still the one investigators mean by blockchain analysis: the chain shows the flows, and a name from somewhere else labels the cluster.
| What happened | What it connects | Who says so |
|---|---|---|
| You reuse an address | Every payment to that address shares one history | bitcoin.org: use a new address for every payment. People who paid you should not be able to see your other addresses. |
| You spend two coins in one payment | Those inputs are treated as one owner's | Chainalysis names co-spends as one of the clustering inputs. |
| The wallet sends you change | The change address gets clustered with the spend | The change address is a public field of the transaction, and change analysis is part of the same clustering. |
| You publish the address | The address is your name, and any later move from it inherits that | Posting an address on a site or a social network taints later transfers to your other addresses. |
| An exchange or a shop knows you | The cluster meets a legal name | Receiving goods or services is where identity usually enters. |
| Your node announces the transaction | An observer can log the IP that first relayed it | The network is peer-to-peer. Relays can be logged. A full node also relays other people's transactions, so a node can be mistaken for the source. |
A wallet you run creates its addresses privately. bitcoin.org's line is that the addresses "are created privately by each user's wallets," and only become public once they are used. A wallet an exchange holds for you is not that. The company already has your name, and the addresses it assigns are inside its cluster before you spend. Running the software yourself moves the problem to the places you later pay, and to the IP that announces the transaction. Every payment from your own wallet still lands on the same public chain.
Running your own node does not take you off that list. bitcoin.org's point about full nodes is the opposite of a privacy guarantee: they relay everyone's transactions, which makes the true source harder to pick out, and they can still be logged. The step it names for the IP, specifically, is Tor, so the address of the computer is not what gets written down. Tor hides the computer from that log. It does not hide the transaction from the chain, and it does not hide you from an exchange that already has your name. How that fits the rest of holding and spending crypto is the wider page. This one is the ledger.
What CoinJoin changes, and what it does not
A coinjoin is one transaction built by several people so that an outsider cannot be sure which input paid which output. A 2025 paper from Masaryk University, posted on arXiv, defines it that way: a collaborative transaction "attempting to improve the users' privacy" by "obfuscating the link between the addresses of their inputs and outputs." bitcoin.org's privacy page still talks about "join[ing] random users' transactions together" as work in progress, and about mixing services as something you hand coins to. Those are different objects. A mixing service takes your coins and sends you different ones. A coinjoin is a transaction you sign with other people. The older page's warning still applies to the service: you trust the operator not to steal the coins and not to keep a log, legality "might vary" by country, and mixing "becomes increasingly difficult" for larger amounts.
The measured limit on coinjoin is not that the transaction fails. It is what people do afterwards. The Masaryk researchers adapted BlockSci to real coinjoins and found an average drop of 10 to 50 percent in the post-mix anonymity set for three coordinated designs: Whirlpool, Wasabi 1.x and Wasabi 2.x. The drop is largest in the first day and, in their words, negligible a year after the coinjoin. The behaviour that shrinks the set is ordinary: combining several mixed outputs into one payment, or sending an output to a regulated exchange that knows your name. Their conclusion is the part a slogan leaves out. Even with that behaviour, "correctly attributing the coins to their owners is still very difficult." CoinJoin works in the narrow sense that the mapping stays ambiguous. It does not survive a later payment to somewhere that already knows who you are, and the anonymity set you were shown on the day is not the set you still have a day later.
Wasabi's default coordinator, the service that organised those collaborative transactions, stopped. The v2.0.8 release notes, published 1 June 2024, say that as of that day "the default coinjoin coordination service provided by zkSNACKs is being discontinued," and that the wallet gained a field where a user can point it at a different coordinator. The software did not vanish. The operator that had been the default path did. A coinjoin still needs other people in the same transaction. A coordinator that has shut down is not those people.
Are Bitcoin mixers legal? The cases, not the slogan
"Are crypto mixers legal?" is three questions wearing one coat. Is the software a crime? Is using it a crime? Is running one, while knowing the money is criminal proceeds, a crime? The documents answer the third, and they answer a sanctions question about an Ethereum mixer that people keep filing under Bitcoin.
| When | What | What it decided |
|---|---|---|
| 8 Aug 2022, reissued that November | OFAC sanctions Tornado Cash | Tornado Cash is Ethereum software, not Bitcoin. OFAC put its smart contracts on the sanctions list after North Korea-linked hacking proceeds moved through it. The Fifth Circuit's later opinion records that designation. |
| 1 June 2024 | Wasabi's default coordinator | zkSNACKs stopped the default coinjoin coordination service. The release is a software note, not a conviction. |
| 26 Nov 2024 | Fifth Circuit, Van Loon | The court held that Tornado Cash's immutable smart contracts are not "property," because nobody can own or exclude people from them, so OFAC exceeded its authority. It reversed and sent the case back. The opinion says the developers included Roman Storm, and that the United States had indicted Storm and Roman Semenov on money-laundering charges. |
| 21 March 2025 | Treasury removes the Tornado Cash sanctions | Treasury said it was exercising discretion to delist Tornado Cash, pointing at a filing in Van Loon. The same release says the department remains "deeply concerned" about North Korea using digital assets, and that people should be careful with transactions that could benefit that. |
| August 2025 | Roman Storm convicted on one count | A Manhattan jury convicted the Tornado Cash developer of conspiring to operate an unlicensed money transmitting business, an offence with a five-year maximum, and could not agree on money-laundering and sanctions conspiracy. |
| 6 and 19 Nov 2025 | Samourai Wallet sentences | CEO Keonne Rodriguez, five years, sentenced 6 November. CTO William Lonergan Hill, four years, sentenced 19 November. The release says they knowingly transmitted over $237 million in criminal proceeds. |
| 25 Aug 2026 | Roman Storm retrial adjourned | Judge Failla adjourned the retrial to 26 April 2027, citing Storm's pending motion for acquittal and his request for a late-April date. Decrypt reports the retrial covers the two counts the jury split on, money laundering and sanctions, and that Storm has not been sentenced on the count he was convicted of. |
| 5 Oct 2026 | FinCEN withdraws two proposals | FinCEN withdrew a proposed rule on recordkeeping for convertible virtual currency and unhosted wallets, and a proposed special measure aimed at convertible virtual currency mixing as a class. The release calls this part of a deregulatory agenda. It is a withdrawal of proposals, not a statute that legalises mixing. |
Samourai is the Bitcoin case, and the facts the Justice Department stood on are specific. Whirlpool, from 2019, batched exchanges among users so the source of a holding was obscured. Ricochet, from 2017, added extra hops between the address that sent and the address that received. From those launches, more than 80,000 bitcoin, valued at over $2 billion at the time, passed through. Fees were estimated at more than $6 million. The release says Hill, on the darknet forum Dread, told a user that Whirlpool was a better option than a competitor for making "dirty BTC" untraceable, and that Rodriguez, in a WhatsApp chat, described mixing as "money laundering for bitcoin." They were sentenced for conspiracy to operate a money transmitting business while knowingly transmitting criminal proceeds. Each was fined $250,000. They paid $6,367,139.69 toward a forfeiture order of $237,832,360.55, the larger number being the traceable criminal proceeds the service had moved. The conviction is not "they wrote privacy software." It is that they ran a transmitting business for proceeds they knew were criminal, and said so.
Tornado Cash is the sanctions case, and it is on Ethereum. Its developer Roman Storm is the person case: convicted on the money-transmitting count in August 2025, with a retrial on the other two counts set for April 2027, so the criminal question is still open. The Fifth Circuit's holding is about the statute: immutable code that no one can own or shut off is not "property" OFAC can block under the International Emergency Economic Powers Act. Treasury's delisting in March 2025 followed that litigation. It is not a finding that the mixing was lawful, and the release keeps the North Korea concern in the next paragraph. What changed for mixers in 2026, in the United States, is narrower still. On 5 October FinCEN pulled two proposed rules, one of them a special measure that would have treated convertible virtual currency mixing as a class of transactions of primary money-laundering concern. A withdrawn proposal is a proposal that is not in force. It does not undo the Samourai sentences, and it does not amend the money-transmitting statute those sentences were built on.
What an ordinary holder should actually do
For someone paying another person, or holding coins they bought on an exchange in their own name, the privacy steps that match the documents are the dull ones. A new address for each payment. No address posted on a website or a social account unless the point of it is to be public. Tor if the worry is the IP of the computer announcing the transaction. Those steps stop the easy joins. They do not make a coin anonymous, and they do not detach it from the exchange that sold it to you.
CoinJoin is a real reduction in how easily one transaction maps inputs to outputs, and the Masaryk paper is the current public measurement of how fast that reduction leaks if the next payment is sloppy. It is not a service to hand coins to. The service version is the one bitcoin.org tells you to distrust, and the one Samourai's founders went to prison for running, as the Justice Department release describes it. Whether a different coin changes this problem, rather than a technique on top of Bitcoin, is a separate question, with its own leaks.
If the coins already passed through a market, a ransomware payment, or a mixer the government has described as transmitting criminal proceeds, the tracing problem is no longer a privacy preference. It is the fact pattern in the Samourai release and in the market seizures.