Timing and burst patterns can leak through encryption, and an adaptive adversary can exploit them. This undermines metadata-only detection in a stand-alone consumer gateway. Therefore, consumer gateways need streaming intrusion detection on encrypted traffic using metadata only, under tight CPU and latency budgets. We present a streaming IDS for stand-alone gateways that instantiates a lightweight two-state unit derived from Network-Optimised Spiking (NOS) dynamics per flow, named NOS-Gate. NOS-Gate scores fixed-length windows of metadata features and, under a $K$-of-$M$ persistence rule, triggers a reversible mitigation that temporarily reduces the flow's weight under weighted fair queueing (WFQ). We evaluate NOS-Gate under timing-controlled evasion using an executable 'worlds' benchmark that specifies benign device processes, auditable attacker budgets, contention structure, and packet-level WFQ replay to quantify queue impact. All methods are calibrated label-free via burn-in quantile thresholding. Across multiple reproducible worlds and malicious episodes, at an achieved $0.1%$ false-positive operating point, NOS-Gate attains 0.952 incident recall versus 0.857 for the best baseline in these runs. Under gating, it reduces p99.9 queueing delay and p99.9 collateral delay with a mean scoring cost of ~ 2.09 μs per flow-window on CPU.

翻译：时序与突发模式可能通过加密泄露信息，自适应攻击者可利用此类特征。这削弱了独立消费级网关中仅基于元数据的检测能力。因此，消费级网关需要在严格CPU与延迟预算下，实现仅基于元数据的加密流量流式入侵检测。本文提出一种面向独立网关的流式入侵检测系统，该系统为每个流实例化一个源自网络优化脉冲（NOS）动力学的轻量级双状态单元，命名为NOS-Gate。NOS-Gate对固定长度的元数据特征窗口进行评分，并在$K$/$M$持续规则下触发可逆缓解机制，该机制会在加权公平队列（WFQ）中临时降低该流的权重。我们使用时序可控规避场景评估NOS-Gate，采用可执行的"场景"基准测试，该基准明确定义了良性设备进程、可审计攻击者预算、竞争结构及数据包级WFQ重放以量化队列影响。所有方法均通过预热分位数阈值进行无标签校准。在多个可复现场景与恶意事件中，当达到0.1%误报率操作点时，NOS-Gate实现0.952的事件召回率，优于同批次最佳基线的0.857。在门控机制下，系统将p99.9排队延迟与p99.9连带延迟平均降低，每个流窗口在CPU上的平均评分成本约为2.09微秒。