Antminer X9
Monero ASIC Miner
1000KH
HASHRATE
2.47W/KH
EFFICIENCY
2470W
POWER
£861.54
EST. MONTHLY
205
DAYS
EST. ROI
This guide explains BIP 326 anti-fee-sniping in plain English. It covers the problem behind the BIP, why it matters and whether the proposal is part of Bitcoin today.
TL;DR
- What it is: BIP 326 is a Draft wallet policy for transactions spending Taproot outputs. It proposes choosing between absolute nLockTime and a one-block relative nSequence value to discourage fee sniping while providing ordinary-looking cover traffic for contract protocols that use a one-block delay against transaction pinning.
- Why it matters: BIP 326 combines anti-fee-sniping with privacy cover for one-block contract delays. Because it remains Draft, implementations should pin the chosen policy, preserve existing sequence constraints and test every input-age and replacement interaction.
- Current position: BIP 326 is a Draft wallet policy for transactions spending Taproot outputs.
BIP 326 anti-fee-sniping in simple English
BIP 326 anti-fee-sniping: The BIP is Draft, Applications and Specification. Wallets may implement different anti-fee-sniping policies. Support cannot be assumed from an address type alone.
Simple example
A node operator is checking BIP 326 anti-fee-sniping. Restricting a transaction to the current chain tip reduces a miner’s ability to rebuild an earlier block and include the transaction there for its fee.
Key terms in plain English
- BIP:
- Bitcoin Improvement Proposal: a document describing a proposed rule, standard or process. Its status must be checked separately.
- Consensus:
- The shared rules full nodes use to decide whether blocks and transactions are valid.
- Taproot:
- A Bitcoin upgrade that added new signature and script options for spending outputs.
- Node:
- A computer running Bitcoin software that checks data and communicates with other peers.
Status and scope
The BIP is Draft, Applications and Specification. Wallets may implement different anti-fee-sniping policies; support cannot be assumed from an address type alone.
Fee-sniping goal
Restricting a transaction to the current chain tip reduces a miner’s ability to rebuild an earlier block and include the transaction there for its fee. The policy still permits ordinary next-block confirmation.
Two mechanisms
The proposal suggests a 50% choice between an absolute nLockTime based on current height and relative nSequence. With multiple inputs, a relative value applies to at least one randomly selected input.
Absolute branch
For sufficiently confirmed inputs, nLockTime uses the current height with occasional random backdating for privacy. At least one non-final sequence is required for absolute locktime to take effect.
Relative branch
An nSequence of one requires the spent output to be at least one block old. That also resembles contract transactions using a one-block CSV delay to make unconfirmed-output pinning harder.
Compatibility
Very recent inputs cannot always use the same branch, and sequence values interact with RBF, relative locktime and contract requirements. Wallets must preserve stronger existing constraints.
How specialists test it
Developers test the proposal with made-up data on an isolated test network. They check normal cases and deliberately invalid cases. Different implementations should reach the same result before anyone relies on the proposal.
Frequently asked questions
What is the main point of BIP 326 anti-fee-sniping?
BIP 326 anti-fee-sniping: The BIP is Draft, Applications and Specification. Wallets may implement different anti-fee-sniping policies.
For BIP 326 anti-fee-sniping, what should a beginner know about status and scope?
The BIP is Draft, Applications and Specification. Wallets may implement different anti-fee-sniping policies.
For BIP 326 anti-fee-sniping, what should a beginner know about fee-sniping goal?
Restricting a transaction to the current chain tip reduces a miner’s ability to rebuild an earlier block and include the transaction there for its fee.
For BIP 326 anti-fee-sniping, what should a beginner know about two mechanisms?
The proposal suggests a 50% choice between an absolute nLockTime based on current height and relative nSequence.
Conclusion
BIP 326 combines anti-fee-sniping with privacy cover for one-block contract delays. Because it remains Draft, implementations should pin the chosen policy, preserve existing sequence constraints and test every input-age and replacement interaction.
Primary sources
- BIP 326 Anti-fee-sniping in Taproot transactions
- BIP 68 Relative lock-time using consensus-enforced sequence numbers
Check the current specification status and the documentation for the exact implementation you operate before moving production funds or changing a mining node.
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