Bitcoin privacy has come a long way since the early days of Bitcoin. Once marketed as anonymous, Bitcoin can be best described as a pseudonymous currency and monetary system. It does not need user personal information whatsoever to function, but companies built around it often associate user public keys — Bitcoin accounts — with user information. They do this to comply with legacy financial regimes, and in some cases, for ease of use.
As a result, users might share or expose personal information to such companies as their home IP address, which can be used to identify the users’ internet service provider, and from there, the users’ physical address. As well as their personal name, phone number, shipping address, etc. All of this information in the wrong hands can put people at risk of physical and economic harm.
It is important to note that Bitcoin does not fundamentally have a privacy problem, as many critics suggest. The modern world has a privacy problem, which it has so far failed to address, leading to regular hacks of user data across every aspect of society, from the banking sector to social networks, from government agencies to the military. The digital society we increasingly inhabit is more often than not incapable of securing user data.
Bitcoin, unlike all other comparable institutions, does not need user data to function. It is actually one of the few financial tools available for the privacy-conscious individual. Cash is the other alternative, which limits the distance at which transactions can be made and brings with it a full bag of other downsides.
But, as a digital system, can Bitcoin actually be used privately, given how prominent KYCed exchanges are, and how data-hungry modern software companies have become? The answer to this question might surprise you.
Privacy from whom?
Depending on the jurisdiction you live in and the local laws or state of your country, some risks or threats are more pressing than others. Some countries throughout the world have at times imposed heavy capital controls on their citizens, often simply enforcing the cash grabs at the banking level. Bitcoin, if held in self-custody and with the right amount of privacy, can protect users from this threat.
In other cases, the nation state is stable enough, but organized crime has run amok, leading to targeted phishing schemes and even kidnappings, like in the case of France, where honest and hard-working individuals pay their crypto taxes, and as a result of local laws, enter the public record as having crypto. Leading to an alarming rise in related home invasions.
Last but not least, there are activists who might be operating under oppressive regimes, debanked and isolated from civil institutions, Bitcoin used in subtle ways can be their only monetary respite. Depending on the situation, some tools and tactics will be better for the job than others.
Privacy also does not mean that you can not be a law-abiding citizen. Strong privacy laws exist in many countries, meant to protect civilians from a variety of threats, while also enabling compliance with tax laws, for example. Privacy does not mean you have something to hide, as Joseph Goebbels, Hitler’s infamous chief of propaganda, once suggested. Instead, it is the ability to choose who you disclose your business to. It is a fundamental pillar of democracy.
Network Privacy
First things first, we have to protect your IP address, the ID your internet service provider gives your computer devices, including your mobile phone. The most popular way to deal with this is to get a VPN.
Not all VPNs are created equal; however, many are rumored to keep logs and sell your data. On this front, it’s important to do deeper research than the marketing and ask around from people who are paranoid enough to know better.
In the Bitcoin space, Mullvad VPN has a good reputation. They have been accepting Bitcoin for their services for a very long time, and are super easy to use. They are used alongside Tor and have an option to block all traffic that does not go through the VPN. One account can support multiple devices, including mobile.
Tor Browser, the infamous gateway into the dark web, is also an important tool to have handy. Many privacy tools we will discuss below support Tor connectivity, often having the required libraries built in, so you just have to push a button on the app to use the Tor network. The apps will be a little bit slower, as Tor does its anonymization magic, just FYI. Brave Browser also deserves a mention here, as it blocks most advertisement tracking and has built-in Tor support.
Getting Bitcoin Privately
The biggest challenge to Bitcoin privacy is actually how users accumulate it. Exchanges, broker-like private companies that facilitate the trade of bitcoin for fiat currency, have emerged as the most efficient and effective way to buy bitcoin. They have managed to survive hostile legal regimes, hacker groups and overzealous law-enforcement agencies by often over-complying with financial regulations that require them to collect massive amounts of personal user data.
Privacy-preserving alternatives to buy and sell bitcoin for fiat have, in turn, been harassed by government agencies regularly, often failing to survive or keep their market foothold against centralized alternatives. An excellent example of this dynamic was the first major peer to peer bitcoin to fiat exchange called LocalBitcoins, which shut down after 10 years of operation since at least 2013. The company faced increasing pressure from regulators in Finland, forced to implement KYC in 2019, and eventually shut down during the 2023 bear market and Operation Chokepoint 2.0.
LocalBitcoins connected buyers and sellers, serving as an escrow for Bitcoin, while the fiat went from the buyer to the seller’s bank account. LocalBitcoins, which pioneered the model, never touched the fiat and did not know the banking information of the seller. Such information would only move up the chain to the operators in the case of disputes. If both buyer and seller were happy with the fiat transfer, the BTC was released from escrow to the buyer.
This semi-decentralized exchange model, pioneered by LocalBitcoins, is generally called a P2P Bitcoin exchange, though many variations of it exist, with a wide range of privacy trade-offs, over the years.
Today, Bisq.network is perhaps one of the most renowned predecessors of LocalBitcoins. Taking a page from the centralized downfall of LocalBitcoins, Bisq attempted to create a Tor-anonymized, decentralized trading platform to allow buyers and sellers of bitcoin to connect all over the world. Bisq still operates today and has a variety of software tools available. Users can run Bisq on their local machines and control their account with their phones with Bisq Connect, or they can simply be notified of trade alerts via Bisq Notifications. There’s also a dedicated mobile app called Bisq Easy.
Volume for Bisq is estimated at almost 5 million dollars a month, which is low by centralized exchange standards, but good enough for civilian-grade dollar cost average purchases over time. It’s important to understand a couple of things when using Bisq. First, you should always pick a counterparty with a very high reputation. You should also pay attention to the commission they charge. It is normal for sellers to charge 5% above spot price or more, so look for the cheapest, highest-reputation option. The Bisq Easy app has a great user interface and teaches users new to P2P the basics quite well.
There’s a variety of other P2P exchanges and platforms in active use throughout the world. As a general rule, when doing P2P, it is best to keep purchases or trades small enough that you don’t take unnecessary risks. They should be significant enough to be worth your time, but any amounts above $10,000 is probably way too much. The Dollar cost average strategy, as a result, works very well with P2P stacking.
Another way to get Bitcoin with good privacy is to find your local Bitcoin community. Many major cities throughout the world have active Bitcoin communities. If there are none where you live, you might be surprised how many people show up if you start a Bitcoin meetup. From there, slow trust building with local bitcoiners might open up the opportunity to buy some BTC from them for cash. Many bitcoiners get paid in bitcoin for their work and often need to sell some to cover fiat expenses, creating an opportunity for P2P trades in real life.
Last but not least, offer your skills in exchange for Bitcoin, start a project or a Bitcoin dedicated brand. This will give you a great deal of control over how you handle information about your Bitcoin revenue.
Onchain Privacy
However, once you have some Bitcoin, there are a variety of things you can do to keep that information secure from prying eyes. Bitcoin, unlike any other money before it, functions as a public network, with its full transaction history auditable by anyone, though not tied to the holders’ personal information, but instead their public address or pseudonymous Bitcoin account number.
These public addresses live on the blockchain, and data firms can try to connect the dots about who is moving money where, especially when they collaborate with exchanges on data sharing or when other relevant information enters the public domain. Users can protect themselves from onchain analytics by using a variety of tools and tactics.
Run your own node
In order to minimize who you share information with about your addresses and balances, it becomes important for privacy reasons to run your own Bitcoin node, otherwise you are always fundamentally asking someone else running a node, what your balance is. All wallets that don’t explicitly run a Bitcoin full node on your machine have to run one on their servers, or redirect your requests to a public node someone might be hosting for charitable or not-so-charitable reasons.
While having network privacy, such as through the use of a VPN, can protect you from the risks of not running your own node, the next step in that self-sovereign, privacy setup is certainly taking control of the node you query, and thus becoming an active participant in the Bitcoin network.
Sparrow Wallet, an increasingly popular desktop wallet which has excellent support for privacy features, hardware wallets and advanced Bitcoin features like multi-signature accounts and Silent Payments, has great documentation on how to run and use your own node. Their conclusion is that Fulcrum, a wrapper on top of Bitcoin core that makes the blockchain data available to external wallets, is the way to go.
As a desktop wallet, Sparrow would work within your home network, letting you access the Bitcoin blockchain with strong privacy. If you wanted to connect to it from your phone or laptop from outside of your local network, you would need to run a Tor hidden service at home, a Tor tunnel of sorts, to access your node remotely in a secure and private way.
Boltz Exchange
Boltz is a Bitcoin-to-crypto, non-custodial exchange. It never touches fiat, and never holds custody of user funds. Users trade against Boltz using a technology under the hood called atomic swaps which means neither party has to trust the other during the trade, the crypto is moved essentially at the same time from the seller to the buyer and viceversa.
Boltz can be used without sharing any personal information and can be accessed through Tor, allowing Bitcoin users to leverage the benefits of other blockchains and payment networks if they so wish, with strong privacy.
One such network accessible via Boltz is the Liquid blockchain, a Bitcoin-denominated and collateralized federated ‘side chain’ with strong privacy features. Another example is the Lightning network, which has powerful potential privacy benefits as it is fundamentally off-chain, leaving a simple public record. Boltz can be used to convert Bitcoin to stablecoins as well on most major blockchains, letting bitcoiners access the broader crypto industry and its market integrations through a high privacy bridge.
Boltz can be used on their website or by downloading a standalone open source web app. A CLI is also available for advanced users, and since the whole stack is open source, users can even self-host the Boltz suite themselves for their business. Boltz, as a result, removes the need for centralized exchanges to move across blockchain rails, eliminating the corresponding privacy risk.
The Liquid Network
The Liquid Network, a federated blockchain created by Blockstream, is slowly becoming an important infrastructure to the Bitcoin industry. Launched in 2018, the chain is a modified fork of Bitcoin with its native asset LBTC, pegged to Bitcoin directly. To mint LBTC, you have to deposit BTC into the federation’s multisig, and to get your BTC out, you can depeg or sell your LBTC for BTC on a variety of atomic swap exchanges. While its consensus structure is different than Bitcoin’s and fundamentally permissioned, it rests on the shoulders of a double-digit group of industry-leading companies throughout the world, and has remained quite stable since it went live.
One of the interesting things about it is its privacy features; transactions on Liquid have their amounts and asset type encrypted by default. Addresses can be seen to move assets from A to B on-chain, but which asset and how much of it is encrypted, only for the involved parties to see. It uses a cryptographic technique called Confidential Transactions, pioneered by Bitcoin wizards like Adam Back, Andrew Poelstra, Mark Friedenbach, Gregory Maxwell, and Pieter Wuille. Liquid is also quite cheap to use, and has faster block times than Bitcoin, making it an interesting tool in the Bitcoin privacy tool belt, specifically with privacy bridges like Boltz exchange.
Blockstream has a mobile wallet that is quite powerful and easy to use, which supports the liquid network.
Silent Payments
Silent Payments are a novel kind of Bitcoin address that reframes the way auditing of balances happens on Bitcoin. The whole point of being able to see addresses and how much BTC is in them on the blockchain is so that users can easily verify the total supply and thus the economic integrity of the Bitcoin monetary network.
Silent payments (SP) let users receive Bitcoin in such a way that the link between the SP address and the corresponding Bitcoin public address is publicly severed. The technology is quite powerful and has a long history of development in the Bitcoin industry, gaining growing adoption in recent years.
Of the few wallets that can receive Silent Payments so far, Sparrow wallet is likely the best across the board, supporting a full range of privacy features, including connection to the user’s own node. Silent Payment addresses can be reused, so users can generate one and take it on the go, then check their balances on their desktop or laptop using Sparrow. For extra privacy, users can run a Frigate server alongside Sparrow, which deals with the Silent Payments magic in a self-hosted way.
Payjoin
Another notable technology that works quite well with the rest is Payjoin. With a dedicated foundation and wallet support growing every day, this simple transaction-building technique breaks the heuristics used by blockchain analytics to identify individual users and their flows across the chain. Sparrow wallet, alongside many others, supports Payjoin, as it continues to grow into what may become the HTTPS of Bitcoin payments.
Coinjoin
Once the bread and butter of Bitcoin privacy, Coinjoins wallets like Wasabi let you mix your Bitcoin with other people’s in a non-custodial way. The technique has significant upsides when done well, and is still used by many to this day, though it also comes with some tricky downsides. Gustavo, an entrepreneur and writer for Bitcoin Optech, says that “Wasabi works better than ever IMO, and is by far the most liquid and effective bitcoin privacy solution.” Liquidity equates to more privacy when it comes to Coinjoins. “Kruw.io is the dominating coordinator: it has over 97% of the market’s liquidity.” with “30,000 btc volume per month, about 4000 btc of fresh btc inputs.”
Coinjoins became so effective and popular that they led to the landmark Samourai Wallet case, which had its own implementation of the technology, an ongoing cultural fight for the right to privacy.
Gustavo also listed some of the downsides involved with Coinjoins that users should consider, such as the risk that a centralized exchange might be able to tell your bitcoins were moved through a coinjoin, which looks like a big cloud of transactions on-chain. And that there is some known risk of data leaks on the side of the coordinator, a server someone has to run to help users atomically mix coins with each other. However, he believes the technology only continues to improve and patch those holes, saying that “the attack surface has decreased since the last discussion in 2024.”
The Lightning and eCash Networks
Last but not least are the eCash and the Lightning Network. Fundamentally off-chain bitcoin native transaction protocols, they have a key benefit over all the onchain privacy solutions, that they do not leave a footprint on the public blockchain. As a result, privacy is theoretically far easier to achieve. In practice, however, there’s still a lot of work to do, since the most private ways to use the Lightning network are the most difficult from a user experience perspective, requiring the user to run their own Lightning node and manage their own liquidity.
While there are many easy-to-use lightning wallets in the market, most, if not all, require a certain level of data sharing trust with the servers of the wallet company. Something that network privacy can help alleviate.
Ecash is also emerging as a strong privacy technology, though it still falls short on adoption in the West. Wallets like Fedi and Cashu are on the cutting edge, letting users transact with unprecedented privacy in Bitcoin terms, though at the cost of trusting custodial mints, which collateralize the ecash tokens with Bitcoin.
Conclusion
Overall, the tools of Bitcoin privacy continue to improve as the industry’s passion for the topic has not waned. Some are easier to leverage than others. But, as Satoshi Nakamoto has demonstrated, those who take their privacy seriously are the only ones who are able to keep it.