1.3 KiB
Coin selection
Reuse Avoidance
A new wallet flag avoid_reuse has been added (default off). When enabled,
a wallet will distinguish between used and unused addresses, and default to not
use the former in coin selection.
Rescanning the blockchain is required, to correctly mark previously used destinations.
Together with "avoid partial spends" (present as of Bitcoin v0.17), this addresses a serious privacy issue where a malicious user can track spends by peppering a previously paid to address with near-dust outputs, which would then be inadvertently included in future payments.
New RPCs
- A new
setwalletflagRPC sets/unsets flags for an existing wallet.
Updated RPCs
Several RPCs have been updated to include an "avoid_reuse" flag, used to control whether already used addresses should be left out or included in the operation. These include:
- createwallet
- getbalance
- getbalances
- sendtoaddress
In addition, sendtoaddress has been changed to avoid partial spends when avoid_reuse
is enabled (if not already enabled via the -avoidpartialspends command line flag),
as it would otherwise risk using up the "wrong" UTXO for an address reuse case.
The listunspent RPC has also been updated to now include a "reused" bool, for nodes with "avoid_reuse" enabled.