MixyUTXO Traceability
Bitcoin doesn't track account balances — it tracks unspent outputs. That design choice defines every privacy challenge.
Unlike bank accounts with balance fields, Bitcoin wallets hold a set of Unspent Transaction Outputs (UTXOs). Each UTXO references the transaction that created it, forming an immutable ancestry tree back to the coinbase reward that minted those satoshis.
Why traceability follows UTXOs
When you spend, you consume entire UTXOs and create new ones. Analysts follow these links. Merging UTXOs from different sources in one transaction tells the world those sources share an owner — the clustering heuristic.
Coin control matters
Advanced wallets let you select which UTXOs fund a payment. Avoid combining tainted and clean outputs. Label UTXOs by source and purpose.
Breaking the chain
Mixers replace your UTXOs with unrelated ones. CoinJoin makes multiple users' UTXOs indistinguishable within one transaction. Both operate because privacy is fundamentally a UTXO property, not an address property.
Related: fungibility and taint.