Max Hillebrand on Nostr: The best tldr on arkpill.me I can muster so far: tldr of the tldr: trustless offchain ...
The best tldr on arkpill.me I can muster so far:
tldr of the tldr: trustless offchain wabisabi coinjoins, cheap in block space, expensive in capital cost.
Clients "peg in" by sending to a 2-of-2 multisig address with the Ark service provider ASP, this is the creation of a vtxo onchain. After X weeks, the ownership and control of this vtxo transfers to the ASP.
At any time, clients can unilaterally without the help of the ASP peg out, which requires 4 onchain transaction and the expiry of a timelock.
With collaboration of the ASP, that onchain vtxo can then be spent off chain by cosigning with the ASP. In this off chain coinjoin transaction the user receive newly created off chain vtxos. The ASP is a Wabisabi coordinator where users can anonymously register inputs, outputs and signatures.
The onchain footprint of this pool transaction is fixed regardless of the number of users, one or more inputs from the ASP, as well as a shared output that commits to all vtxo outputs of the offchain vtxo coinjoin transaction. So, thousands of offchain vtxos are represented by a single onchain output.
A offchain vtxo can only be spend once, must be spend before the 4 week timelock, and a payment is only finalized, when the pool transaction is confirmed in the blockchain. The offchain vtxo transaction graph should be considered public knoedge, therefore the inputs and outputs must be carefully chosen to ensure privacy.
The ASP also runs a lightning service provider, it accepts (zero conf) vtxos as the first hop of an atomic lightning route to pay any external lightning invoice. The ASP also accepts vtxos for the creation of onchain outputs in the pool transaction (submarine swap). The ASP further accepts onchain or lightning payments in exchange for vtxos. Therefor peg-in and peg-out transactions may be less common, and end-users mainly do swaps.
The big downside, the input side of the pool transaction has to come from the ASP, he can take that from funding / pool utxos that are expired (4 weeks). The value of the pool output is the sum value of all the offchain vtxos in that round. So, if 1000 users each have 5 bitcoin in that round, the ASP needs 5000 btc. The ASP has to bring external liquidity to cover the onchain funding until the users peg-in or the pool transaction timelock expires, at which point those onchain utxos can be used to fund the input of the next pool transaction.
There is a much lower mining cost of the ceremony, but a much larger capital / liquidity cost that the ASP has to cover. The ASP requires a fee structure that includes remixes, and the fee is a percentage of the value of the vtxo.
Final words, Ark is crazy cool tech, shows what's possible with covenants, removes a shit load of blockspace cost, but adds a huge capital cost.
tldr of the tldr: trustless offchain wabisabi coinjoins, cheap in block space, expensive in capital cost.
Clients "peg in" by sending to a 2-of-2 multisig address with the Ark service provider ASP, this is the creation of a vtxo onchain. After X weeks, the ownership and control of this vtxo transfers to the ASP.
At any time, clients can unilaterally without the help of the ASP peg out, which requires 4 onchain transaction and the expiry of a timelock.
With collaboration of the ASP, that onchain vtxo can then be spent off chain by cosigning with the ASP. In this off chain coinjoin transaction the user receive newly created off chain vtxos. The ASP is a Wabisabi coordinator where users can anonymously register inputs, outputs and signatures.
The onchain footprint of this pool transaction is fixed regardless of the number of users, one or more inputs from the ASP, as well as a shared output that commits to all vtxo outputs of the offchain vtxo coinjoin transaction. So, thousands of offchain vtxos are represented by a single onchain output.
A offchain vtxo can only be spend once, must be spend before the 4 week timelock, and a payment is only finalized, when the pool transaction is confirmed in the blockchain. The offchain vtxo transaction graph should be considered public knoedge, therefore the inputs and outputs must be carefully chosen to ensure privacy.
The ASP also runs a lightning service provider, it accepts (zero conf) vtxos as the first hop of an atomic lightning route to pay any external lightning invoice. The ASP also accepts vtxos for the creation of onchain outputs in the pool transaction (submarine swap). The ASP further accepts onchain or lightning payments in exchange for vtxos. Therefor peg-in and peg-out transactions may be less common, and end-users mainly do swaps.
The big downside, the input side of the pool transaction has to come from the ASP, he can take that from funding / pool utxos that are expired (4 weeks). The value of the pool output is the sum value of all the offchain vtxos in that round. So, if 1000 users each have 5 bitcoin in that round, the ASP needs 5000 btc. The ASP has to bring external liquidity to cover the onchain funding until the users peg-in or the pool transaction timelock expires, at which point those onchain utxos can be used to fund the input of the next pool transaction.
There is a much lower mining cost of the ceremony, but a much larger capital / liquidity cost that the ASP has to cover. The ASP requires a fee structure that includes remixes, and the fee is a percentage of the value of the vtxo.
Final words, Ark is crazy cool tech, shows what's possible with covenants, removes a shit load of blockspace cost, but adds a huge capital cost.