Dust Attack
Also: dusting
wallets · intermediate
Sending tiny amounts of bitcoin to many addresses, then watching to see which ones get spent together — linking addresses to the same owner.
Dust attacks exploit a privacy weakness: when you spend a UTXO, you reveal that you control it. Send a dust output (a few hundred sats) to thousands of addresses. When the recipients later co-spend that dust alongside other UTXOs in a single transaction, the chain-analysis firm doing the dusting now knows those UTXOs belong to one entity.
Defenses are simple but require discipline. Modern wallets flag dust UTXOs and let you mark them as "do not spend." Coin-control features (CoinJoin, manual UTXO selection) prevent the dust from being silently mixed in. Some wallets auto-quarantine sub-threshold incoming amounts.
The attack is cheap to launch and pays off when even a small fraction of recipients sweep the dust into a larger transaction. It is one of the better arguments for picking a wallet with strong UTXO management.