Bitcoin developers are discussing removal of explicit replace-by-fee (RBF) signaling from wallet software, as full-RBF has become standard network policy, making the opt-in flag redundant. The legacy signal creates on-chain fingerprints that can reveal wallet software used by users, compromising privacy. Developers propose adopting a common default input sequence number, likely MAX-2, already used by about 75% of transactions, to make transactions from different wallets indistinguishable. This coordinated change aims to eliminate unnecessary tracking vectors. The proposal is in early discussion stages on the developer mailing list.

Key facts

• Full-RBF became standard Bitcoin policy, making explicit RBF signaling redundant.
• Legacy RBF signal creates on-chain fingerprints revealing wallet software used.
• Proposal: adopt common default input sequence number (likely MAX-2).
• Removal requires careful coordination to avoid new fingerprinting vectors.
• Discussion ongoing on Bitcoin developer mailing list.

KeyAudit data perspective