Wallets

Coinjoins

Reclaim your privacy
with collaborative bitcoin transactions.

Bitcoin is open

By design, all bitcoin transactions are publicly visible. That’s great to prevent inflation and fraud without relying on third parties, but it has some privacy drawbacks.

It’s all about the coins

Unspent Transaction Outputs, or UTXOs, are essentially the coins in the Bitcoin network.

Each coin has a distinct transaction history, making all Bitcoin transactions unique and easily trackable.

How a Bitcoin transaction works

A user picks an amount of bitcoin to send (0.7 BTC) to a destination address. To do so, their bitcoin wallet selects at least one spendable coin or UTXO and adds it as an input (1 BTC) in the transaction.
The transaction has two outputs: a payment output (0.7 BTC) and a change output (0.29 BTC), which returns to the user’s wallet. There is also a usual network fee (0.01 BTC to keep it simple in this example).
The user signs the transaction and sends it to the Bitcoin network so a miner can add it to a block to get the network fees. Anyone can verify the transaction status at any time.

Tracking Bitcoin transactions

Bitcoin transactions are public. Is a transaction a payment or a self-spend? Is it a Lightning channel opening? Is it connected to other transactions? It’s a guessing game with popular heuristics that chain analysts use to track bitcoin users.

Payment

If a transaction has two outputs, then it’s likely a payment where the sender receives an unused amount back to their wallet.

Self-Transfer

If there is no change output, then it’s likely that bitcoin did not change hands and that it is a self-spend.

Same Owner

If it’s a payment, it’s likely that all the inputs belong to the same user, connecting unrelated past transactions.

Surveillance is easy & cheap on Bitcoin

There is a whole industry of bitcoin surveillance, referred to as chain analysis.

Public block explorers allow anyone to monitor, record and analyse transactions.

Bitcoin is easily verified by anyone

And technically, due to the transparency of its database, Bitcoin could become one of the most advanced tools for financial surveillance.

By default, that makes privacy for regular users quite low, which is harmful for the personal safety of consumers and commercial interests of businesses.

Do you really have nothing to hide?

Would you want strangers knowing how much money you earn per month or saved in a year?

Or your future spouse knowing you bought her wedding ring before you pop the big question?

Or your employer knowing who you make political donations to?

Privacy is a choice to not share certain information

The choice should be yours. Whether you want to share information publicly or keep some of it personal, should be up to you.

That’s not how Bitcoin works

But you can reclaim your privacy today

Without changing Bitcoin

Hello, Coinjoins!

In a coinjoin, many different users participate together in one single collaborative transaction.

A coinjoin transaction has many standard outputs of the same amounts, which makes it very hard to track them back to their initial inputs.

That allows coinjoin users to conceal the history of their coins from the public to make their UTXOs fungible on the public Bitcoin network.

Heard bad things about coinjoins?

Over 10 years after coinjoins were first discussed, there is still uncertainty about its usage. Let’s bust the Fear, Uncertainty and Doubt (FUD) surrounding coinjoins.

“Coinjoins are pointless. Bitcoin is already anonymous.”

“Coinjoins are illegal.”

“Coinjoins will make it impossible to use exchanges.”

“Coinjoins are only used by criminals.”

“Coinjoins will get your funds stolen.”

“Coinjoins are only for technical users.”

“Coinjoins have high fees.”

“Coinjoins just don’t work.”

“Coinjoins are made by intelligence agencies.”

10.

“Coinjoins give you a false sense of privacy.”