Europol closely monitors Bitcoin wallets offering increased transaction privacy. But that doesn’t deter their developers from always adding more anonymity-focused features, like PayJoin.
BlueWallet, a very complete Bitcoin wallet
BlueWallet has the wind in its sails! Indeed, it integrates many very practical features, such as:
Peer-to-peer bitcoin buying;
Compatibility with many hardware wallets ;
Grouping of transactions;
The connection to its own full node;
A browser and marketplace for Lightning apps.
It also allows payments to be made on the Lightning Network intuitively. Like Samurai Wallet , BlueWallet is focused on the security and privacy of Bitcoin Optimizer transactions. The recent implementation of PayJoin significantly improves the latter.
PayJoin, an improved CoinJoin
CoinJoin allowsits coins to be mixed , which increases the anonymity of the parties to the transaction. Several participantsthus mix several entries within the same transaction. The outputs, of the same amount , go to new addresses. It is then impossible to know their origin.
However, the heuristic of blockchain Bitcoin allows to detect a CoinJoin transaction, because of these outputs to the same amount. So far, we haven’t heard of any platforms or merchants rejecting mixed transactions… But that could change in the future.
This is where PayJoin comes in , a solution proposed by Nicolas Dorier ( BIP 78 ). This type of CoinJoin takes place between two participants , a sender and a receiver. In addition to the sender’s payment, the receiver also includes a UTXO in the transaction.
The entries do not have the same origin: they come from several different entities. It is therefore no longer possible for a blockchain observer to group the sender’s entries.
The exits have different values , so we can no longer infer that it is a CoinJoin. Moreover, these outputs do not reveal the true amount of the payment. Here we have a payment of 0.2 BTC but with two outputs of 0.7 BTC and 0.8 BTC.
Finally, this technique allows the receiver to “ consolidate ” its corners . Instead of ending up with two UTXOs of 0.2 and 0.5 BTC, he now has a UTXO of 0.7 BTC. he will thus save costs if he wishes to spend these coins .
Bold Bitcoin wallet developers
BlueWallet thus joins the family of the most confidential Bitcoin wallets by integrating PayJoin. Wasabi teams have also implemented this solution. Of course, BTCPay Server , Nicolas Dorier’s payment processor, also allows the use of PayJoin.
These techniques, offering more anonymity to Bitcoin users, make the task of blockchain analysis companies more complex… and Europol does not like it at all.