Recent advances in error-corrected qubits have accelerated the timeline for practical quantum computing. It poses a threat to cryptographic primitives used to secure financial systems, government infrastructure, communication networks, and DeFi (Decentralized Finance) ecosystems. This paper introduces a post-quantum secure federated DeFi framework that enables inter-bank collaboration to improve the inclusivity of individuals underserved by local lenders due to limited financial histories. Multiple banks contribute encrypted information batches to a virtual server, where lattice-based Fully Homomorphic Encryption (FHE) enables end-to-end homomorphic computation. The server fuses local data-driven probabilistic assessments, expert beliefs, and verifiable evidence generated by the NASA-IBM Prithvi Geospatial Foundation Model (GFM), in encrypted format. Decentralized technologies are employed to ensure tamper-proof evidence and auditable accountability for all encrypted data exchanges between institutions and the server. The framework is tested on agricultural lending decisions for rural borrowers in Virginia.

翻译：近期容错量子比特的研究进展加速了实用化量子计算的进程，这对保障金融系统、政府基础设施、通信网络及DeFi（去中心化金融）生态系统的密码学原语构成了威胁。本文提出了一种抗量子安全的联邦DeFi框架，该框架支持银行间协作，以提升因金融历史有限而难以获得本地贷款机构服务的个人用户的普惠性。多家银行将加密信息批次提交至虚拟服务器，其中基于格的完全同态加密（FHE）支持端到端同态计算。服务器在加密状态下融合本地数据驱动的概率评估、专家信念以及NASA-IBM Prithvi地理空间基础模型（GFM）生成的可验证证据。采用去中心化技术确保机构与服务器之间所有加密数据交换的防篡改证据和可审计问责性。该框架在弗吉尼亚州农村借款人的农业贷款决策场景中进行了测试。