熔岩貸款協議（v2）：無需信任的比特幣抵押貸款系統

Lava 貸款協議 (v2) 是 Lava 設計的方案，基於離散日誌合約 (DLC)，旨在促進無需信任的比特幣抵押貸款系統。

The Lava Loans protocol (v2) is a scheme designed by Lava building upon Discreet Log Contracts (DLCs) to facilitate a trustless Bitcoin collateralized loan system. The huge implosion in the market last cycle caused by centralized platforms facilitating Bitcoin backed loans showed that left unchecked, such products and services can present a massive systemic risk to the entire market in the ecosystem.

Lava 貸款協議 (v2) 是 Lava 設計的方案，基於離散日誌合約 (DLC)，旨在促進無需信任的比特幣抵押貸款系統。上個週期，由中心化平台促進比特幣支援貸款引起的市場巨大崩潰表明，如果不加控制，此類產品和服務可能會對生態系統中的整個市場帶來巨大的系統性風險。

Lava seeks to provide the same utility users of such centralized platforms sought in a decentralized and atomic fashion, using DLCs.

Lava 尋求使用 DLC，以去中心化和原子方式為此類集中式平台提供相同的實用程式使用者。

DLCs, for those unfamiliar with the concept, are a smart contract designed to settle a certain way depending on the outcome of some event outside of the Bitcoin protocol, i.e. the price of Bitcoin, the outcome of a sports game, etc. This is done by depending on an oracle, or a set of multiple oracles, who sign a message attesting to the actual outcome of the real world event. These signed messages are used as the basis for adapter signatures that unlock specific pre-signed transactions that settle the contract a certain way.

對於那些不熟悉這個概念的人來說，DLC 是一種智能合約，旨在根據比特幣協議之外的某些事件的結果（即比特幣的價格、體育比賽的結果等）以某種方式進行結算。這些簽章訊息用作適配器簽章的基礎，適配器簽章解鎖以某種方式結算合約的特定預簽章交易。

The benefit of DLCs is they can be done privately. As long as the oracle(s) publish the keys they will use to sign outcomes for specific events at specific times, any user can take that information and construct pre-signed transactions to settle correctly based on the range of possible outcomes without the oracle ever knowing that a contract exists. The oracle simply publicly broadcasts the signed message at the appropriate time, and that gives both users all the needed information to settle the contract correctly.

DLC 的好處是它們可以私下完成。只要預言機發布了他們將用來在特定時間簽署特定事件結果的密鑰，任何用戶都可以獲取該資訊並建立預簽名交易，以便根據可能結果的範圍進行正確結算，而無需預言機知道合約的存在。預言機只是在適當的時間公開廣播簽名的訊息，這為兩個用戶提供了正確解決合約所需的所有資訊。

Lava is designed to make use of a modified variant of DLCs, in addition to stablecoins on other networks, to facilitate a bitcoin collateralized loan that can be entered into atomically and trustlessly (i.e. guaranteeing that the lender cannot gain control of bitcoin without releasing control of the stablecoin to the borrower).

Lava 的設計目的是利用DLC 的修改變體以及其他網路上的穩定幣，以促進可以自動且無需信任地簽訂的比特幣抵押貸款（即保證貸款人在不釋放對比特幣的控制權的情況下無法獲得對比特幣的控制權）。

Instantiation

實例化

The funding of the DLC is a two step process in the Lava protocol, given the requirement that the stablecoins given in exchange for the collateral being locked in the contract must be atomic. In the first phase, the borrower creates a script that allows them to claim their coin back after a timelock, or allows the lender to complete the funding with a hash preimage and signature from the borrower. They then sign a transaction that moves the coins from this staging address into the DLC. The lender then exchanges a hashlock for use later in the protocol with the borrower.

在 Lava 協議中，DLC 的融資過程分為兩步，因為要求交換鎖定在合約中的抵押品的穩定幣必須是原子的。在第一階段，借款人創建一個腳本，允許他們在時間鎖定後收回他們的代幣，或允許貸方使用借款人的哈希原像和簽名完成融資。然後，他們簽署一項交易，將代幣從該暫存地址轉移到 DLC 中。然後，貸方與借方交換哈希鎖，以便稍後在協議中使用。

From this point, the lender needs to fund a similar atomic exchange contract with the borrower on the chain hosting the stablecoin. This contract allows the borrower to claim the stablecoins with the same preimage used to finalize the DLC on Bitcoin, or the lender to reclaim the stablecoins after a timeout. The contract on the alt-chain is also collateralized with extra stablecoins that remain in the contract, and cannot be claimed back by the lender until after the completion of the contract. This will be explained later.

從這一點來看，貸方需要為託管穩定幣的鏈上的借款人提供類似的原子交換合約資金。該合約允許借款人以用於完成比特幣 DLC 的相同原像索取穩定幣，或允許貸方在超時後收回穩定幣。山寨鏈上的合約也以合約中剩餘的額外穩定幣作為抵押，在合約完成之前，貸方無法收回。這將在後面解釋。

After the setup phase, the borrower releases the preimage to the hashlock, claims the stablecoins, and enables the lender to move the bitcoin from the staging address into a finalized DLC. At this point the contract is active.

在設定階段之後，借款人將原像釋放到哈希鎖，索取穩定幣，並使貸款人能夠將比特幣從暫存地址轉移到最終的 DLC 中。此時合約處於活躍狀態。

Execution

執行

During the lifetime of the contract there are three ways that the loan can be settled, either at expiry or during its lifetime. Firstly, the lender can execute the DLC with the borrower’s adaptor signature, and an attestation of the current price from the oracle(s). Secondly, the borrower can execute with the lender’s adaptor signature and an attestation from the oracle(s). Lastly, the borrower can repay the loan on the alt-chain, enabling them to claim back bitcoin collateral when the lender claims their repayment and stablecoin collateral. All of these execution paths disperse the appropriate amount of bitcoin to both parties based on the market price attested to by the oracle(s).

在合約有效期內，可以透過三種方式解決貸款，即到期時或合約有效期內。首先，貸方可以使用借方的適配器簽名以及來自預言機的當前價格證明來執行 DLC。其次，借款人可以使用出借人的適配器簽名和來自預言機的證明來執行。最後，借款人可以在山寨鏈上償還貸款，這樣當貸方要求還款和穩定幣抵押品時，他們就可以收回比特幣抵押品。所有這些執行路徑都會根據預言機證明的市場價格向雙方分配適當數量的比特幣。

The repayment path makes use of the second hash preimage that the lender generated during the setup. The DLC script is modified allowing the borrower to claim back the collateral at any time during the contract lifetime as long as they have the preimage to that the lender has generated. On the alt-chain, the stablecoin contract is also established to require the lender to reveal that preimage to claim back their repayment and collateral.

還款路徑利用貸方在設定期間產生的第二個哈希原像。 DLC 腳本經過修改，允許借款人在合約有效期內隨時索取抵押品，只要他們擁有貸方生成的原像即可。在替代鏈上，也建立了穩定幣合約，要求貸方披露原像以收回還款和抵押品。

This construction for repayment is added to deal with the incentive where a repayment is made, but the lender does not finalize the repayment because the interest payment on the loan outstanding is greater than the interest that could be earned from them issuing a new loan. This is also the reason that the lender is required to collateralize the alt-chain contract with extra stablecoins, creating an incentive for them to redeem a repayment. Without doing so, they cannot claim the collateral back, thereby creating an incentive for them to honor the repayment and release the bitcoin collateral even when there is a financial incentive due to the interest payments to not do so.

添加這種還款結構是為了應對還款的激勵，但貸方並未最終確定還款，因為未償還貸款的利息支付大於他們發放新貸款可賺取的利息。這也是貸款人需要用額外的穩定幣來抵押替代鏈合約的原因，從而激勵他們贖回還款。如果不這樣做，他們就無法收回抵押品，從而激勵他們兌現還款並釋放比特幣抵押品，即使由於支付利息而有經濟動機不這樣做。

Once the lender releases the preimage to claim back the repayment and the stablecoin collateral, the borrower is then capable

一旦貸方釋放原像以收回還款和穩定幣抵押品，借款人就有能力