Fresh-Challenge VDF 证明用于模型相对响应延迟
Fresh-Challenge VDF Attestations for Model-Relative Response Latency
- Nazarbayev University（纳扎尔巴耶夫大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文提出 Fresh-Challenge VDF 证明（FCLA）协议，将可验证延迟函数绑定不可预测挑战与消息，在明确假设下提供模型相对的响应延迟证据，并给出基准实现验证评估与验证的分离。
AI中文摘要：
一个有限的验证者能否获得关于顺序计算响应延迟的公开的、模型相对的证据？可验证延迟函数（VDF）在原则上使这成为可能：评估需要 T 个顺序步骤，而验证在安全参数上高效，并且对于标准构造，在 T 的数值上是多对数级的。因此，延迟可以大到天文数字般难以评估，却能简洁地表示并可行地检查。仅针对所选消息的 VDF 证明是不够的，因为它可能被预先计算。我们详细说明并分析了 Fresh-Challenge VDF 证明（FCLA），这是一种协议组合，将 VDF 绑定到一个不可预测的公开挑战、一条消息以及可独立审计的发布和接收记录。在关于 VDF 顺序性、挑战源、见证日志以及对手顺序评估率的校准上限的明确假设下，一个被接受的 FCLA 记录与该有界模型中对手在挑战后生成不一致。该结果既不识别具名声称者，也不排除中继、外包或更快的未建模机器。对公开参考实现的基准测试证实了在一台有记录的机器上评估与验证之间预期的经验分离。我们的贡献是协议/设计分析和基准测试的参考实现层，而非新的 VDF 构造或密码学原语。
英文摘要：
Can a finite verifier obtain public, model-relative evidence about response latency for sequential computation? Verifiable delay functions (VDFs) make this possible in principle: evaluation requires T sequential steps, whereas verification is efficient in the security parameter and polylogarithmic in the numerical value of T for standard constructions. Thus a delay can be astronomically large to evaluate yet succinctly represented and feasibly checked. A VDF proof for a chosen message alone is insufficient because it may be precomputed. We specify and analyze Fresh-Challenge VDF Attestations (FCLA), a protocol composition that binds a VDF to an unpredictable public challenge, a message, and independently auditable release and receipt records. Under explicit assumptions about VDF sequentiality, the challenge source, witness logs, and a calibrated upper bound on an adversary's sequential evaluation rate, an accepted FCLA transcript is inconsistent with post-challenge generation by an adversary in that bounded model. The result neither identifies a named claimant nor excludes relaying, outsourcing, or a faster unmodeled machine. A benchmark of the public reference implementation confirms the expected empirical separation between evaluation and verification on one documented machine. Our contribution is a protocol/design analysis and benchmarked reference implementation layer, not a new VDF construction or cryptographic primitive.
