Boarding the Ark
Boarding Transaction
The boarding transaction is a streamlined funding process for VTXOs. This method allows Alice to swap onchain funds to VTXO(s) without requiring interactive steps with the Server, simplifying the initial funding phase and enhancing the efficiency of the protocol.
Alice initiates the process by creating a taproot boarding address. The key-path is disabled and the script tree includes two spending contidions:
- Exit path: Alice can unlock the funds after a timeout period of 6 months.
- Cooperative path: Alice and the Server cooperate to spend the funds.
| Inputs | Outputs |
|---|---|
| Alice’s UTXO | (Alice after 6 months) or (Alice + Server) |
Join the Ark
Once the boarding transaction is confirmed onchain, Alice can join the Ark by submitting the UTXO to the Server, that in exchange creates a VTXO for her in next VTXO tree. The boarding UTXO is included as input of the round transaction and co-signed by Alice and Server using the collaborative path.
Before including the UTXO in the round, the Server verifies that the UTXO is not spendable by Alice alone. The exit path must be invalid according to the exit timeout.
Exit the boarding contract
Unilateral
After the boarding transaction is confirmed, Alice can exit the boarding contract by spending alone the UTXO with the exit path. However, this path is only valid after the timeout period of 6 months. After the timeout, Alice can spend the UTXO without the Server's cooperation.
Collaborative
If Alice wants to exit the boarding contract before the timeout, she can ask the Server for cooperation and spend the UTXO with the collaborative path and swap it for a UTXO instead of a VTXO.