For years, users looking to speed up their transactions on the Bitcoin blockchain relied on a handy optional feature that essentially says, “You may want to replace this transaction with a higher fee.”
But what started out as a useful tool has become redundant and a bit of a privacy issue, leading some developers to discuss possible ways to remove it.
Let’s first look at so-called replacement-for-fee (RBF) signage and then analyze the developers’ proposals.
Replace with fare signaling (RBF)
Imagine sending a paper check in the mail, but the postal system is overloaded and congested. To ensure your payment doesn’t get stuck, the check has a small checkbox that says, “I reserve the right to cancel this check and issue a new one with a higher rush fee if it is late.” (The higher rate, of course, is an incentive for the postal system to prioritize your transaction.)
This feature is called Replacement for Fee (RBF) in the Bitcoin ecosystem. For years, when you sent bitcoins, your wallet would let you flip a switch, telling the network that you might want to “raise fees” to speed up your transaction later.
