熔岩贷款协议（v2）：无需信任的比特币抵押贷款系统

Lava 贷款协议 (v2) 是 Lava 设计的一种方案，基于离散日志合约 (DLC)，旨在促进无需信任的比特币抵押贷款系统。

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 贷款协议 (v2) 是 Lava 设计的一种方案，基于离散日志合约 (DLC)，旨在促进无需信任的比特币抵押贷款系统。上个周期，由中心化平台促进比特币支持贷款引起的市场巨大崩溃表明，如果不加控制，此类产品和服务可能会给生态系统中的整个市场带来巨大的系统性风险。

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

Lava 寻求使用 DLC，以去中心化和原子方式为此类集中式平台提供相同的实用程序用户。

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.

对于那些不熟悉这个概念的人来说，DLC 是一种智能合约，旨在根据比特币协议之外的某些事件的结果（即比特币的价格、体育比赛的结果等）以某种方式进行结算。通过依赖一个预言机或一组多个预言机来签署一条消息，证明现实世界事件的实际结果。这些签名消息用作适配器签名的基础，适配器签名解锁以某种方式结算合同的特定预签名事务。

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 的好处是它们可以私下完成。只要预言机发布了他们将用来在特定时间签署特定事件结果的密钥，任何用户都可以获取该信息并构建预签名交易，以便根据可能结果的范围进行正确结算，而无需预言机知道合同的存在。预言机只是在适当的时间公开广播签名的消息，这为两个用户提供了正确解决合同所需的所有信息。

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 的设计目的是利用 DLC 的修改变体以及其他网络上的稳定币，以促进可以自动且无需信任地签订的比特币抵押贷款（即保证贷款人在不释放对比特币的控制权的情况下无法获得对比特币的控制权）。向借款人提供稳定币）。

Instantiation

实例化

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 协议中，DLC 的融资过程分为两步，因为要求交换锁定在合约中的抵押品的稳定币必须是原子的。在第一阶段，借款人创建一个脚本，允许他们在时间锁定后收回他们的代币，或者允许贷方使用借款人的哈希原像和签名完成融资。然后，他们签署一项交易，将代币从该暂存地址转移到 DLC 中。然后，贷方与借方交换哈希锁，以便稍后在协议中使用。

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.

从这一点来看，贷方需要为托管稳定币的链上的借款人提供类似的原子交换合约资金。该合约允许借款人以用于完成比特币 DLC 的相同原像索取稳定币，或者允许贷方在超时后收回稳定币。山寨链上的合约还以合约中剩余的额外稳定币作为抵押，在合约完成之前，贷方无法收回。这将在后面解释。

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.

设置阶段结束后，借款人将原像释放到哈希锁，索取稳定币，并使贷款人能够将比特币从暂存地址转移到最终的 DLC 中。此时合约处于活跃状态。

Execution

执行

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).

在合同有效期内，可以通过三种方式解决贷款，即到期时或合同有效期内。首先，贷方可以使用借方的适配器签名以及来自预言机的当前价格证明来执行 DLC。其次，借款人可以使用出借人的适配器签名和来自预言机的证明来执行。最后，借款人可以在山寨链上偿还贷款，这样当贷方要求还款和稳定币抵押品时，他们就可以收回比特币抵押品。所有这些执行路径都会根据预言机证明的市场价格向双方分配适当数量的比特币。

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.

还款路径利用贷方在设置期间生成的第二哈希原像。 DLC 脚本经过修改，允许借款人在合同有效期内随时索取抵押品，只要他们拥有贷方生成的原像即可。在替代链上，还建立了稳定币合约，要求贷方披露原像以收回还款和抵押品。

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.

添加这种还款结构是为了应对还款的激励，但贷方并未最终确定还款，因为未偿还贷款的利息支付大于他们发放新贷款可赚取的利息。这也是贷款人需要用额外的稳定币来抵押替代链合约的原因，从而激励他们赎回还款。如果不这样做，他们就无法收回抵押品，从而激励他们兑现还款并释放比特币抵押品，即使由于支付利息而有经济动机不这样做。

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

一旦贷方释放原像以收回还款和稳定币抵押品，借款人就有能力