Bitcoin privacy and CoinJoin : after Samourai

Bitcoin is pseudo-anonymous, not anonymous. An address is not your name, but it is permanent and public. Every euro or sat passing through your address leaves an immutable trace that chain analysis companies (Chainalysis, Elliptic, TRM Labs) cross-reference with other data (exchange×ExchangeService that lets you buy, sell and swap cryptocurrencies against fiat money. Examples : Kraken, Coinbase, Bitstamp, Bitvavo. Most are custodial.See in the lexicon → KYC×KYC (Know Your Customer)Mandatory identification procedure that regulated platforms apply to their users : ID document, proof of address, and so on.See in the lexicon →, outgoing transactions, network metadata×MetadataData that describes other data. For a Bitcoin transaction : size, fees, type. For an email : sender, date, subject, without the content itself.See in the lexicon →) to identify the holder.

24 April 2024 marked a turning point. The US Department of Justice indicted Samourai Wallet×Samourai WalletPrivacy-focused wallet shut down under US regulatory pressure in April 2024. A heavy blow for mainstream Bitcoin privacy.See in the lexicon →'s founders for money laundering and unlicensed money transmitter operation, and shut down Whirlpool, the largest operational CoinJoin×CoinJoinTransaction-mixing technique where several users combine their UTXOs into one large transaction, in order to break the input / output link.See in the lexicon → service at the time. The impact was immediate : disappearance of a widely-used tool, freeze of similar centralised coordinators (Wasabi also ceased its coordination service in June 2024), and shift toward peer-to-peer alternatives.

This article maps the Bitcoin privacy landscape in 2026 : what chain analysis sees, the techniques still available after Samourai (peer-to-peer JoinMarket, PayJoin×PayJoin (P2EP)Variant of CoinJoin where the recipient quietly adds one of their UTXOs as an input. Improves privacy and breaks heuristic analysis.See in the lexicon →, BIP×BIP (Bitcoin Improvement Proposal)Standard document that describes a proposed improvement to the Bitcoin protocol. Numbered (BIP 32, BIP 39, BIP 174, and so on). Open, public process on GitHub.See in the lexicon → 352 silent payments, BIP 158 filters), the operational OPSEC×OPSEC (operational security)Discipline of not exposing exploitable information: not revealing holdings, separating identities and addresses, limiting metadata. A bitcoin holder's first line of defence.See in the lexicon → of a bitcoiner×BitcoinerPerson interested in Bitcoin, who holds some and adheres more or less to its values (individual sovereignty, sound money, decentralisation).See in the lexicon → wallet×WalletSoftware or device that manages your Bitcoin keys and lets you sign transactions. A wallet does not really « hold » your bitcoins, it holds the keys that prove you own them.See in the lexicon →, and the trade-off between privacy, convenience and KYC risk.

What chain analysis sees

Chain analysis exploits three main heuristics to link addresses to a user. First heuristic : common input ownership. If a transaction takes as input several UTXOs from several addresses, those addresses probably belong to the same wallet×WalletSoftware or device that manages your Bitcoin keys and lets you sign transactions. A wallet does not really « hold » your bitcoins, it holds the keys that prove you own them.See in the lexicon →. This rule topics addresses into wallets. Second heuristic : change detection. When a transaction has two outputs, one is typically the recipient, the other is change returning to the sender. Several signals (round amount, address type matching sender, change often first output) help guess which is which.

Third heuristic : address reuse. If you receive twice on the same address, your two entries are trivially linked. If you pay to a merchant who reuses an address, your payments to that merchant are linked to each other. Address reuse is the most common and most damaging mistake for privacy. All good modern wallets generate a new address per reception, but many users insist on reusing.

Off-chain, KYC×KYC (Know Your Customer)Mandatory identification procedure that regulated platforms apply to their users : ID document, proof of address, and so on.See in the lexicon → exchanges provide the definitive link between address and real identity. Once Chainalysis knows a given address belongs to John Doe's Kraken account, its inputs and outputs are traceable several nodes upstream and downstream. The clustering heuristic propagates identification from address to address via UTXOs. A single mistake can retroactively compromise several years of history. This is what motivates mixing techniques and strict OPSEC×OPSEC (operational security)Discipline of not exposing exploitable information: not revealing holdings, separating identities and addresses, limiting metadata. A bitcoin holder's first line of defence.See in the lexicon →.

The April 2024 Samourai shutdown

Samourai Wallet×Samourai WalletPrivacy-focused wallet shut down under US regulatory pressure in April 2024. A heavy blow for mainstream Bitcoin privacy.See in the lexicon →, founded in 2015 by Keonne Rodriguez and William Hill, had become the dominant CoinJoin×CoinJoinTransaction-mixing technique where several users combine their UTXOs into one large transaction, in order to break the input / output link.See in the lexicon → service from 2019 onward with Whirlpool, a coordinator running a Zerolink-type mixing with fixed-size pools (0.001, 0.01, 0.05, 0.5 BTC). The service claimed having processed several billion dollars of CoinJoin coordination between 2019 and 2024. It was the most used for mainstream Bitcoin privacy.

On 24 April 2024, the US DOJ released an indictment against Rodriguez and Hill for conspiracy to commit money laundering and operation of an unlicensed money transmitting business. The DOJ argument : by operating a CoinJoin coordinator, Samourai knowingly facilitated laundering and operated as a money transmitter without FinCEN license. Servers were seized, Whirlpool ceased, the Samourai app was pulled from the Play Store, the still-active Whirlpool coordinators were shut down.

Wasabi Wallet×WalletSoftware or device that manages your Bitcoin keys and lets you sign transactions. A wallet does not really « hold » your bitcoins, it holds the keys that prove you own them.See in the lexicon → (Swiss competitor, operated by zkSNACKs) announced in June 2024 the preemptive shutdown×ShutdownDeliberate stopping of a service or device. In Bitcoin, the term is often used for the Samourai Wallet shutdown in 2024 or Blockfolio in 2022 : abrupt end of a service.See in the lexicon → of its CoinJoin coordination service to avoid similar exposure. The consequence : within a few months, the two largest centralised CoinJoin coordinators had disappeared. Users turned toward decentralised tools (JoinMarket), native techniques (PayJoin×PayJoin (P2EP)Variant of CoinJoin where the recipient quietly adds one of their UTXOs as an input. Improves privacy and breaks heuristic analysis.See in the lexicon →), or abandoned CoinJoin. The Rodriguez/Hill trial continues in 2026 and its outcome will likely determine the legal framework of CoinJoin coordinators in Western jurisdictions.

JoinMarket : the peer-to-peer way

JoinMarket, launched in 2015 by Adam Gibson (waxwing), is the decentralised alternative to Whirlpool and Wasabi. Instead of a central coordinator, JoinMarket runs on a peer-to-peer market : market makers (the yield generators) offer their liquidity waiting for a taker to initiate a CoinJoin×CoinJoinTransaction-mixing technique where several users combine their UTXOs into one large transaction, in order to break the input / output link.See in the lexicon →. The taker pays a sats commission to the makers, in exchange×ExchangeService that lets you buy, sell and swap cryptocurrencies against fiat money. Examples : Kraken, Coinbase, Bitstamp, Bitvavo. Most are custodial.See in the lexicon → for shuffling their UTXOs via a standard CoinJoin transaction.

The operational advantage : no central coordinator to legally attack, so not the same legal risk profile as Samourai. The system has run since 2015 without interruption and has demonstrated its resilience. The downside : the interface is rougher than Samourai or Wasabi (CLI or ORC in desktop mode), fees vary depending on maker supply (typically 0.1 to 0.5 % of mixed amount), and liquidity is less concentrated so the mixing takes longer.

In 2026, JoinMarket has become the de facto successor for users wanting CoinJoin. Development is carried by AdamISZ (Adam Gibson) and several contributors since 2015. Joinmarket-clientserver is the maintained implementation. For a serious user who wants to understand, reading the original CoinJoin whitepaper×Whitepaper (white paper)Nine-page founding document published by Satoshi Nakamoto on 31 October 2008, "Bitcoin: A Peer-to-Peer Electronic Cash System". It describes how the network works, ahead of its launch in January 2009.See in the lexicon → and the JoinMarket Wiki docs is an excellent investment. For less technical use, you need to wait for graphical wallets to plug into JoinMarket, which is happening progressively (Sparrow Wallet×WalletSoftware or device that manages your Bitcoin keys and lets you sign transactions. A wallet does not really « hold » your bitcoins, it holds the keys that prove you own them.See in the lexicon → announced a JoinMarket integration planned for 2026).

PayJoin : breaking heuristics without CoinJoin

PayJoin×PayJoin (P2EP)Variant of CoinJoin where the recipient quietly adds one of their UTXOs as an input. Improves privacy and breaks heuristic analysis.See in the lexicon → (BIP×BIP (Bitcoin Improvement Proposal)Standard document that describes a proposed improvement to the Bitcoin protocol. Numbered (BIP 32, BIP 39, BIP 174, and so on). Open, public process on GitHub.See in the lexicon → 78, Nicolas Dorier, 2019) is a radically different approach : instead of mixing UTXOs with strangers, you mix them with those of the recipient of a legitimate payment. When Alice pays Bob, their PayJoin transaction has two inputs (one from Alice, one from Bob) and two outputs (the transferred amount, plus change). To an outside observer, the transaction looks like an internal move of a single wallet×WalletSoftware or device that manages your Bitcoin keys and lets you sign transactions. A wallet does not really « hold » your bitcoins, it holds the keys that prove you own them.See in the lexicon →, without either party revealing to the other more information than in a classic payment.

The major PayJoin advantage : it breaks the common input ownership heuristic. An observer can no longer presume that input UTXOs belong to the same wallet. This degrades clustering quality across all network transactions, not just PayJoin ones (positive pollution effect : the more PayJoin is used, the less heuristics work everywhere).

PayJoin requires the recipient's cooperation (they must have a PayJoin endpoint available). In 2026, BTCPay Server enables it by default, several merchants use it, Sparrow Wallet and Specter support PayJoin signing and broadcast on the payer side. Adoption remains lower than CoinJoin×CoinJoinTransaction-mixing technique where several users combine their UTXOs into one large transaction, in order to break the input / output link.See in the lexicon → because it needs two technically-equipped parties, but it is growing and has the advantage of no coordinator-style legal risk profile (each party signs their own inputs, like any payment).

BIP 158 filters and BIP 352 silent payments

BIP×BIP (Bitcoin Improvement Proposal)Standard document that describes a proposed improvement to the Bitcoin protocol. Numbered (BIP 32, BIP 39, BIP 174, and so on). Open, public process on GitHub.See in the lexicon → 158 (Olaoluwa Osuntokun, Alex Akselrod, Jim Posen, 2017) introduces compact block filters, a cryptographic primitive letting a light wallet×WalletSoftware or device that manages your Bitcoin keys and lets you sign transactions. A wallet does not really « hold » your bitcoins, it holds the keys that prove you own them.See in the lexicon → ask a Bitcoin node×NodeComputer that runs the Bitcoin software and takes part in the network by validating blocks and transactions. A « full node » keeps a complete copy of the blockchain.See in the lexicon → if it has transactions matching its addresses without revealing which. The wallet downloads one filter per block (~30 KB), tests locally if its addresses could match, and only downloads full blocks where a match is possible. It is the opposite of the traditional SPV model (BIP 37) which asks the node to filter for the wallet, revealing the addresses to the node.

BIP 158 thus improves the privacy of a light wallet connecting to a public node or a third-party service. Phoenix, Aqua, Sparrow and several other wallets use it by default. It is a silent but real improvement of network privacy : your wallet does not tell a remote node "here are my 50 addresses" but just "send me the compact filters".

BIP 352 silent payments (Ruben Somsen, josibake, 2023, Proposed status) goes further. Instead of a different address per reception (needed with BIP 32/39/44 to avoid address reuse), silent payments allow a single static publicly shared address whose ECDH cryptography guarantees each received payment lands on the blockchain×BlockchainA public, shared ledger that records every Bitcoin transaction in blocks linked together cryptographically. Each participant in the network keeps a copy.See in the lexicon → at a distinct address. No more addresses to regenerate, no more shared xpub×xpub (extended public key)Extended public key. Lets a read-only wallet see addresses and balances without being able to sign. Used for tracking and observation.See in the lexicon → management, no more reuse problem. The sender only needs the static silent payment address. Activation without soft-fork×Fork (soft fork, hard fork)Change to the protocol rules. A soft fork stays compatible with old nodes (SegWit, Taproot); a hard fork creates a separate chain (Bitcoin Cash in 2017).See in the lexicon → (compatible with existing Taproot×TaprootMajor Bitcoin upgrade activated in November 2021 (BIP 341). Brings more privacy, scripting flexibility and the efficiency of Schnorr signatures.See in the lexicon →), Sparrow implementation in 2025, general availability hoped for 2026-2027.

Operational OPSEC and privacy / KYC trade-off

The OPSEC×OPSEC (operational security)Discipline of not exposing exploitable information: not revealing holdings, separating identities and addresses, limiting metadata. A bitcoin holder's first line of defence.See in the lexicon → of a Bitcoin wallet×WalletSoftware or device that manages your Bitcoin keys and lets you sign transactions. A wallet does not really « hold » your bitcoins, it holds the keys that prove you own them.See in the lexicon → boils down to simple but strict rules. Never reuse a receive address (most modern wallets handle this, but verify×Don't trust, verifyBitcoiner mantra. Trust no one (bank, government, exchange, influencer), verify on your own through your own node.See in the lexicon →). Separate logical pots : one wallet for KYC×KYC (Know Your Customer)Mandatory identification procedure that regulated platforms apply to their users : ID document, proof of address, and so on.See in the lexicon → purchases from the exchange×ExchangeService that lets you buy, sell and swap cryptocurrencies against fiat money. Examples : Kraken, Coinbase, Bitstamp, Bitvavo. Most are custodial.See in the lexicon →, one wallet for cold storage×Cold storageStoring bitcoins on an offline wallet that is not connected to the Internet. Maximum security for amounts you are not spending.See in the lexicon →, one wallet for daily payments. The bridge between these pots ideally goes through CoinJoin×CoinJoinTransaction-mixing technique where several users combine their UTXOs into one large transaction, in order to break the input / output link.See in the lexicon →, PayJoin×PayJoin (P2EP)Variant of CoinJoin where the recipient quietly adds one of their UTXOs as an input. Improves privacy and breaks heuristic analysis.See in the lexicon →, or a Lightning detour, not a direct transaction.

Network side : your wallet connects to a node×NodeComputer that runs the Bitcoin software and takes part in the network by validating blocks and transactions. A « full node » keeps a complete copy of the blockchain.See in the lexicon →. If that node is public or third-party, it sees all your queries (watched addresses, transaction broadcasts). Running your own Bitcoin Core×Bitcoin CoreReference implementation of the Bitcoin software, written in C++ and maintained by an open-source community. This is the software that most nodes run.See in the lexicon → node (see the Running a node article) removes this leak. Otherwise, using a light wallet supporting BIP×BIP (Bitcoin Improvement Proposal)Standard document that describes a proposed improvement to the Bitcoin protocol. Numbered (BIP 32, BIP 39, BIP 174, and so on). Open, public process on GitHub.See in the lexicon → 158 and routing the network layer through Tor significantly reduces the profile.

The privacy / convenience / KYC trade-off is unavoidable. Strong KYC (buy on Kraken, withdraw on exchange resale) : max convenience, near-zero privacy. Light KYC (Relai, Pocket Bitcoin) : reasonable convenience, partial privacy. No-KYC (Bisq×Bisq, HodlHodl, AgoraDeskNo-KYC P2P platforms where you buy bitcoin directly from another individual via multisig escrow.See in the lexicon →, HodlHodl×Bisq, HodlHodl, AgoraDeskNo-KYC P2P platforms where you buy bitcoin directly from another individual via multisig escrow.See in the lexicon →, AgoraDesk×Bisq, HodlHodl, AgoraDeskNo-KYC P2P platforms where you buy bitcoin directly from another individual via multisig escrow.See in the lexicon →) : lower convenience, good privacy but not absolute. Post-acquisition mixing (JoinMarket, PayJoin) : adds a privacy layer to any acquisition path. No path is perfect ; choose based on your threat model and time tolerance. For 90 % of bitcoiners, aiming for pure no-KYC is neither achievable nor necessary. For the 10 % who need it, JoinMarket + personal node + Tor remain the 2026 standard.