PANDORA: Lightweight Adversarial Defense for Edge IoT using Uncertainty-Aware Metric Learning

—The rapid augmentation of Internet of Things (IoT) devices that are resource-constrained in nature has significantly expanded the attack surface, exposed critical vulnerabilities in the network. As a result, traditional Intrusion Detection Systems (IDS), which rely on static, signature-based approaches, have become increasingly obsolete. Modern adversaries now employ sophisticated, automated, and often novel (zero-day) attacks that can easily bypass such conventional defenses. Moreover, the existing IDS models with machine learning often fail in real-world scenarios to handle challenges like concept drift and an inability to generalize to unseen threats. To address these gaps, we introduce PANDORA (Probabilistic Adversarial Network Defense Over Resource-constrained Architectures), a novel, end-to-end framework for detecting zero-day attacks on edge devices. PANDORA makes three key contributions: 1) It learns uncertainty-aware probabilistic embeddings to create robust representations of network traffic; 2) It introduces a novel Probabilistic Manifold Structuring and Distance (PMSD) Loss function that enables effective zero-shot generalization; and 3) It utilizes an efficient Mamba-Mixture of Experts (MoE) architecture for on-device deployment. To validate our approach, we also introduce the TTDFIoTIDS2025 dataset, a new, high-fidelity benchmark featuring complex, programmatically generated attacks. Our extensive evaluations demonstrate that PANDORA significantly outperforms state-of-the-art models, achieving an F1-score of 0.971 with just 10-shot adaptation on CICIDS2017. Critically, it achieves up to 99% accuracy in zero-shot detection under domain shift and, when deployed on a Raspberry Pi, maintains a low memory footprint of 24 MB and a throughput of up to 4.26 flows/sec, proving its practical viability for real-time edge security.