Continuous-time decryption mixnets can anonymously route data packets with end to end latency that can be as low as a second, making them usable for a variety of applications. Such mixnets however lack verifiable reliability properties that ensure the correct processing and delivery of packets, while existing verifiability mechanisms are incompatible with scalable low latency continuous-time mixnets due to imposing overheads measuring in minutes to hours. This work addresses this gap by proposing a scheme that can estimate reliability scores for links and nodes forming a continuous-time mixnet where some form of credentials authorize clients to send traffic. The scores can be computed publicly by all participants from a set of measurement packets that are eventually revealed and act as a random sample of the traffic, without affecting mixnet transmission latency for client packets. Our scheme relies on VRF-based routing, a novel primitive that ensures that legitimate client packets follow the routing policy of the mixnet, as well as randomly generating unforgeable measurement packets. We experimentally validate our construction both in unreliable and adversarial settings, demonstrating its feasibility.

翻译：连续时间解密混合网络能够以低至秒级的端到端延迟匿名路由数据包，使其适用于多种应用场景。然而，此类混合网络缺乏可验证的可靠性特性来确保数据包的正确处理与投递，而现有的可验证机制由于引入数分钟至数小时量级的开销，无法与可扩展的低延迟连续时间混合网络兼容。本研究通过提出一种可靠性评分估计方案来解决这一缺陷，该方案可为构成连续时间混合网络的链路与节点评估可靠性分数，其中某种形式的凭证授权客户端发送流量。所有参与者均可从一组最终被公开的测量数据包中公开计算这些分数，这些数据包作为流量的随机样本，且不会影响客户端数据包在混合网络中的传输延迟。我们的方案基于VRF路由——一种确保合法客户端数据包遵循混合网络路由策略的新型原语，同时能随机生成不可伪造的测量数据包。我们在不可靠及对抗性环境中通过实验验证了该构建的可行性。