Uneconomical outputs
Also covering Dust
Uneconomical outputs are transaction outputs that are worth less than the fees it will cost to spend them. To prevent users from creating uneconomical outputs that will increase the size of the UTXO set, Bitcoin Core and other nodes refuse to relay or mine transactions with outputs below a certain value, called the dust limit.
Terminology note: sometimes dust is used as a synonym for uneconomical outputs or, more generically, low value outputs. This can create confusion, such as in the case of dust attacks which involve amounts just barely above the dust limit. Optech recommends using uneconomical outputs for outputs that aren’t worth the cost to spend them, reserving the term dust for references specific to the dust limit.
Primary code and documentation
Optech newsletter and website mentions
2023
2022
- Discussion about allowing uneconomical outputs that are part of a transaction package
- BDK #689 allows a wallet to create a transaction that violates the dust limit
- Question about problems removing uneconomical outputs from UTXO set
2021
- Discussion about removing the dust limit for one particular case
- Bitcoin Core #22863 documents P2TR dust amount
- BOLTs #894 specifies various checks related to uneconomical payments in LN
- Multiple implementations of LN vulnerable to uneconomical spending CVEs
- Multiple implementations of BOLTs #894 which allow using a lower commitment tx dust limit
- Rust-Lightning #1009 adds a
max_dust_htlc_exposure_msatchannel configuration option - Discussion about removing the dust limit
2020
2019
- Question: how was the dust limit chosen?
- Question: how does LN handle dust and uneconomical payments?
See also
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