Quick Answer:
Bitcoin transactions are not anonymous but pseudonymous, as they can be traced through the public ledger known as the blockchain. Each transaction is linked to addresses, which are strings of alphanumeric characters not directly tied to personal identity, but if an address is linked to an individual, their transactions can be tracked.
Identity linkage can occur through public address sharing, exchange transactions due to KYC/AML laws, hosted wallet services, using Bitcoin for purchases, ISP tracking, and blockchain analytics. However, users can enhance their privacy by using new addresses for each transaction, picking secure wallets like hardware wallets or privacy-focused desktop wallets, running a full Bitcoin client, buying Bitcoin anonymously, protecting their IP address with tools like TOR or VPNs, and mixing coins using tumblers or by trading Bitcoin for privacy coins.
Maintaining complete privacy with Bitcoin is challenging and often comes at the cost of efficiency, but with the right balance, it’s possible to significantly increase the privacy of Bitcoin transactions.
How is Bitcoin anonymous? Well, the short answer is that it is not! As it turns out, the rumors of Bitcoin’s anonymity have been greatly exaggerated.
In the early days of Bitcoin, the nature of blockchain technology and its possibilities were not well grasped by the general population or even by Bitcoin users themselves. This led to a lot of misinformation about Bitcoin, chiefly that Bitcoin transactions are completely anonymous, and that they cannot be traced to personal identities. In fact, there are many ways your identity can be traced through Bitcoin transactions.
Don’t worry, though. Some of these methods can only be used by law enforcement agencies in order to uncover cryptocurrency related crimes. There are some precautions you can take to protect your privacy from other bad faith actors such as hackers or scammers.
This guide will help you understand how your Bitcoin transactions can be traced to you and what steps you can take in order to enhance your privacy.
What’s a Blockchain?
Bitcoin is a decentralized, peer-to-peer digital currency. This means there is no need for a central authority, for example a bank, to control and monitor transactions to prevent fraud. Instead, all Bitcoin transactions are recorded permanently on a public ledger called the Bitcoin blockchain.
The value of each transaction, its date and time, and the addresses of senders and receivers are all recorded on the blockchain and can be accessed by anyone on the Bitcoin network.
This means that when you make a Bitcoin transaction, the ledger is updated to reflect the Bitcoin exchange between the sender and receiver addresses. These addresses are essentially strings of alphanumeric characters that are generated from your private key. Even calling them addresses is a bit of a misnomer because you can generate a new address for each transaction.
The addresses are not related to you or your personal information directly.
At a first glance, this may all seem fool-proof for anonymity purposes. However, the reality is more complex. If an address is compromised, or in other words if it gets linked to your identity, it becomes possible to trace how much BTC you own as well as all the transactions the same address is used for.
So, Bitcoin is considered pseudonymous instead of anonymous. If your pseudonym i.e. your address is leaked, your Bitcoin transactions can be traced back to you.
How Can Bitcoins Be Traced?
As we discussed above, Bitcoin transactions are pseudonymous. All the transactions on the blockchain are connected to each other through encrypted addresses. All users in the Bitcoin network can access the balance of any given address and the transaction history associated with it.
In theory, it is possible to protect your privacy by making sure your addresses can’t be linked to you by using new addresses for each transaction. This was the method originally suggested by Satoshi Nakamoto, the mysterious person or group of people who launched Bitcoin into existence.
However, in reality, it has become quite hard to protect your pseudonymity even when using new addresses for each transaction. There are many ways your identity can be associated with your Bitcoin transactions. We compiled a list of some common ways your identity can be linked to your Bitcoin.
Sharing Your Address Publicly
Remember that Bitcoin addresses are like pseudonyms. If you want to maintain pseudonymity, it is counterproductive to share a Bitcoin address together with your personal information. Anybody can check through your address and see how much Bitcoin you have along with all the transactions associated with that address. Due to the nature of the internet, it is likely that your name will be associated with the address forever if you share this information online.
Buying and Trading on Exchanges
If you want to buy Bitcoin on a crypto exchange, you should know that most exchanges have to comply with Anti-Money Laundering (AML) and Know Your Customer (KYC) regulations. This means that you need to submit identifying information such as your first name and last name, or a scanned copy of your national ID, your phone number, or some other personal identifiers in order to open an exchange account.
The exchanges can also collect your IP addresses. This way, you are linked to your Bitcoin transactions on the exchange from the beginning.
If the exchange’s security is breached, your personal information and Bitcoin transactions can be leaked online. Of course, exchanges will share your personal information with governmental authorities if required by law.
Using Hosted Wallets
You need a Bitcoin wallet to store your security keys, send and receive bitcoins, and monitor Bitcoin balances. Each wallet comes with a private and public security key and the latter is used to generate your Bitcoin addresses.
Exchange service wallets and other online wallets host your information on third-party servers. They have access to your addresses and any additional information you provide. They can also monitor your IP address.
Some of these wallets store your private keys as well, which means that if a security breach occurs, you not only lose your information but your bitcoins as well because the private key is compromised. This unfortunately has happened before as we know from the Mt Gox incident.
Using Bitcoin to Make Purchases
When you are using Bitcoin to purchase goods and services, your Bitcoin address can be identified by the merchant or the Bitcoin payment processor you use. If you are using Bitcoin to buy things that will be delivered to you, you will also have to provide a name and an address which can easily link your identity to your transactions.
Internet Service Provider
You give your Internet Service Provider (ISP) your personal information when you subscribe to their services and they are able to match your IP address to your personal identity. ISPs can analyse which transactions relayed over the Bitcoin network belong to your IP address. So, they can effectively match your identity to your Bitcoin.
Blockchain Analytics
As stated above, the Bitcoin blockchain is a public ledger that permanently records all Bitcoin transactions. Each transaction on the blockchain connects different addresses together. All this public data can be analyzed and sorted through the use of analytical tools called blockchain analytics.
Studies show that researchers can use analytical tools to paint a picture of the Bitcoin network by tracking transactions and identifying users’ profiles. Government authorities often work with companies providing blockchain analytics services in order to uncover Bitcoin-related crimes.
How to Enhance Your Privacy
Privacy enthusiasts shouldn’t despair. There are several precautions you can take in order to protect the pseudonymity of your cryptocurrency transactions. Since you know there are several ways different actors can track your Bitcoin, you can choose the best methods to protect yourself from bad faith actors like hackers and scammers.
Use a New Address for Each Transaction
Using a different address for each transaction is the first and easiest step towards enhancing your privacy. However, there is still a risk with multi-input transactions. Multi-input transactions mean that you are using funds from different addresses for the same transaction.
In these transactions, there is a risk that all your input addresses can be uncovered if one of them has already been compromised.
In order to improve your security, you can use multiple wallets. When you use different wallets for different purposes, it becomes exceedingly hard to group your transactions together.
Pick a Secure Wallet
Hard drive wallets are considered as the safest option to store your keys. They are not as convenient as some of the other storage options, but they are the best option if you are worried about privacy. There are many cryptocurrency wallets designed specifically for security purposes.
As an alternative to hardware wallets, you can also use privacy-centred desktop wallets that also offer BTC mixer services such as Coinjoin. You don’t have to commit to one type of wallet either, as using multiple wallets can increase your privacy.
Run a Full Client
While Bitcoin is a peer-to-peer network, not every user is a fully validating node in the system.
Most Bitcoin users prefer to use what is known as thin clients as their Bitcoin wallet software. This is because thin clients don’t have to download and verify the entire Blockchain. They only track the transactions related to the addresses connected to the wallet.
This makes them particularly efficient in terms of speed and disk space storage. However, they are not great for privacy. Users’ IP and Bitcoin addresses connected to the wallet are exposed if they are not running a full node.
Buying Bitcoin Anonymously
If you are not comfortable with a cryptocurrency exchange service owning your personal information, you can try to buy Bitcoin anonymously.
There are cryptocurrency exchanges that sell BTC for fiat currencies without identity verification, but since your purchase would be connected to your bank account, this is not ideal. Your best option is buying Bitcoin with cash.
One way you can do this is to find someone willing to sell Bitcoin for cash around your location, but this might not be really easy.
Another way is to check whether there is a Bitcoin ATM you can use nearby. You can buy Bitcoin from these ATM’s anonymously using cash. A third option would be buying Bitcoin in exchange for another cryptocurrency, which you can do anonymously on decentralized exchanges (DEXs).
Protect Your IP Address
Your computer’s IP address can be a dead giveaway for your real-world identity. ISPs and cryptocurrency exchange sites collect IP addresses, and they can match them to your transactions. Once your IP address is known, your identity can be exposed. Thankfully, there are several steps you can take to secure your IP address.
Your first option is hiding your IP address through TOR. TOR is a free and powerful program for browsing the internet privately. You can use the Tor browser to minimize the risks posed by accessing cryptocurrency exchanges, since it will hide your computer’s IP address.
You can take a step further and use a Virtual Private Network (VPN) service to enhance your privacy. VPN services hide your IP address and block or spoof your location. You can also access Tor through a VPN which adds another layer of security to your browsing.
Mixing Your Coins
Another method to obfuscate your cryptocurrency transactions is using coin mixers or coin tumblers. These online services help mix address traceability. For a fee, you can send your coins to these services and receive new bitcoins at a new address.
In theory, they break the traceability of Bitcoin transactions. The problem is that these services are run by third-party providers and there is no way of knowing if they are keeping records of mixing operations. You have to trust them to be discreet and not lose or steal your coins.
If you want to mix your coins for increased privacy, make sure you pick a trustworthy service. Also, you should know that mixing services can work for small amounts of BTC and it is very hard to prevent traceability for big sums of BTC.
There is another way you can mix your coins without relying on a third-party mixer. You can trade your BTC with privacy coins. There are some altcoins that are privacy-centric, such as Monero, that you can buy with Bitcoin. You can simply convert your BTC to a privacy coin and forward them to a new address. You are then free to convert them back to BTC.
A Few Words Before You Go…
It is a common misconception that Bitcoin is an anonymous and untraceable digital currency. Bitcoin relies on blockchain technology which is a public collection of all BTC transaction records.
While Bitcoin relies on cryptography to secure the safety and permanency of the records, the transactions are not encrypted. Anyone can access the blockchain and check out transaction history associated with a given Bitcoin address.
This means that Bitcoin is pseudonymous and user identities can be exposed through the various methods we discussed above. There are several precautions users can take to enhance their privacy and keep their pseudonymity. Some of these are quite basic rules such as not sharing Bitcoin addresses online or using new addresses for transactions. Others are a little bit more complex, but can be performed easily with some research.
Keeping absolute pseudonymity with Bitcoin can be a challenging task. It takes time, energy, and resources to manage your Bitcoin privacy. More privacy in the Bitcoin network usually means less efficiency. Ideally, you will find a good balance between privacy and practicality.