Today the BTC redeem tx is built once with a fixed fee baked in, and Bob's adaptor signature commits to that fee via Sighash::All (swap-core/src/bitcoin/redeem.rs). Alice can't bump the fee unilaterally, and with external_redeem_address she also can't CPFP.
Have Bob produce N encrypted signatures over N parallel TxRedeems at different feerates (e.g. 2/5/10/25/50 sat/vB), with sequence = 0xFFFFFFFD so they RBF-replace each other. Alice picks a tier at broadcast based on current mempool, and replaces with a higher tier if it gets stuck.
No sighash change, no anchor output, works with external redeem addresses.
Today the BTC redeem tx is built once with a fixed fee baked in, and Bob's adaptor signature commits to that fee via
Sighash::All(swap-core/src/bitcoin/redeem.rs). Alice can't bump the fee unilaterally, and withexternal_redeem_addressshe also can't CPFP.Have Bob produce N encrypted signatures over N parallel
TxRedeems at different feerates (e.g. 2/5/10/25/50 sat/vB), withsequence = 0xFFFFFFFDso they RBF-replace each other. Alice picks a tier at broadcast based on current mempool, and replaces with a higher tier if it gets stuck.No sighash change, no anchor output, works with external redeem addresses.