Notes

• Proposes a cryptographic collateralized loan protocol for limited‑scripting blockchains (e.g., Bitcoin) without smart contracts.
• Introduces VGES, a new primitive to encrypt signatures on a graph, ensuring decryption only after valid repayment paths.
• Relies on oracles but uses only basic on‑chain transactions, enabling wide compatibility.
• Provides two constructions with trade‑off between on‑chain transaction count and off‑chain computation.
• Implementation shows efficiency on commodity hardware, deployable on Bitcoin‑like chains.
• Extends the possibility of contract‑free, cross‑chain cryptographic lending.

• 提出面向有限脚本区块链（如比特币）的抵押贷款密码协议，无需智能合约。
• 引入新原语VGES（可验证图加密签名），确保签名仅在图路径还款完成后解密。
• 协议依赖预言机，但利用链上基本交易实现逻辑，兼容性广。
• 给出两种构造，提供链上交易数量与链下计算开销的权衡。
• 实现评估显示在普通硬件上均高效，可部署于比特币等链。
• 纯密码学方法扩展了跨链无合约借贷的可能性。