CoinJoinXT

CoinJoinXT is a proposed Bitcoin privacy protocol that extends the basic idea behind CoinJoin. Instead of combining everyone into one shared transaction, participants build a connected set of transactions, often described as a proposed transaction graph, that moves funds through intermediate outputs and returns each participant the value they put in.

That structure aims to make the resulting on-chain footprint look less like a single obvious mix. If the graph blends in with ordinary transaction activity, chain analysis has a harder time identifying where the coordinated protocol starts and ends. Some designs also preserve CoinJoin-style ambiguity even after the construction is recognized, because observers still cannot reliably match equal-valued outputs back to specific inputs.

The tradeoffs are extra block space, more coordination, and stricter transaction requirements. Early CoinJoinXT designs leaned on [SegWit][/topics/segwit] to avoid transaction malleability problems, and later writeups describe variants that would benefit from [Schnorr][/topics/taproot]-style aggregated signing. CoinJoinXT remains a research direction rather than a widely deployed wallet feature, though JoinMarket contributors and other privacy researchers have published design notes and proof-of-concept code.

References

• en.bitcoin.it: CoinJoinXT
• Chaumian CoinJoinXT
• AdamISZ/CoinJoinXT-POC