Author: ecurrencyhodler 2023-05-25 16:06:31
Published on: 2023-05-25T16:06:31+00:00
In an email response to the Bitcoin Protocol Discussion group, ecurrencyhodler thanks David for his clear and concise write-up about the ARK proposal. He notes that it appears ARK is using PSBT's + covenants to secure unconfirmed transactions, which reduces on-chain footprint but raises concerns about mempool size and fee environment within the 10-minute block. The email also includes a message from adiabat, who has questions about how the pool transactions work in ARK, including what happens every 5 seconds and what prevents ASPs from taking all the money. David A. Harding responds to Burak Keceli's ARK proposal with interest and a concern about receiving payments on the protocol, as it seems to require waiting for the transaction containing that payment to confirm to a sufficient depth. He provides a summary of the ARK protocol, which involves Alice running an ARK service provider and broadcasting a new unconfirmed on-chain transaction every 5 seconds, with three outputs: a change output, connector output, and commitment output. Bob wants to deposit 1 BTC with Alice and sends her an unsigned PSBT with an input of his.The email thread on the bitcoin-dev mailing list discusses the process of collaborative (or trustless) coin joins, where two parties can mix their coins without trusting each other. The process involves creating a partially signed bitcoin transaction (PSBT) that includes inputs from both parties and outputs that pay each party their respective amounts. The PSBT is updated with commitment and connector outputs, which allow for various withdrawal options for Bob. These options include unilaterally withdrawing his funds after a 24-hour delay, collaboratively withdrawing by trading his UTXO for a new UTXO funded by Alice, or collaboratively trading commitments to extend the time before Alice can claim the funds. Other payment options are also possible, such as making an unconditioned payment to Carol or making a conditional payment depending on whether she reveals a secret or not. However, users are not well-protected during reorgs, and Alice may need to prove that no funds they receive derive from any deposit less than safe_confirmation_depth blocks. Atomicity is ensured in the process, and connector outputs from different deposits can be used as inputs into the same transaction, merging their histories.
Updated on: 2023-06-01T16:55:39.888367+00:00