arXiv Machine Learning

Byzantine Accountability Without Consensus: Strong Eventual Consistency for Non-Associative, Stochastic, Robust Aggregation

arXiv:2607. 10305v1 Announce Type: cross Abstract: Byzantine-robust aggregation rules such as multi-Krum assume a central coordinator, and decentralising them is obstructed by the rules themselves: they are globally coupled, non-associative, and discontinuous, so an ulpscale perturbation can flip the selected subset, moving the output by a non-vanishing amount.

arXiv AI
Sep 24

Preregistered Belief Revision Contracts

The paper introduces Preregistered Belief Revision Contracts (PBRC), a protocol that separates open communication from admissible epistemic change in deliberative multi-agent systems. PBRC fixes evidence triggers, revision operators, priority rules, and fallback policies, requiring that belief changes cite preregistered triggers and validated evidence tokens. The authors prove that PBRC prevents confidence inflation from conformity, preserves auditability, ensures epistemic accountability, and characterizes enforced belief trajectories under token-invariant contracts.

By Saad Alqithami
arXiv Machine Learning
4d ago

Byzantine-Robust Federated RAG via Aligned Calibration and Fixed-Membership Conformal Prediction

This paper introduces a Byzantine‑robust federated retrieval‑augmented generation (RAG) framework that uses aligned calibration and fixed‑membership conformal prediction to ensure that the answer set contains the correct answer with a chosen probability, even when some nodes are compromised. By having all nodes score the same calibration questions and retaining only candidates that could be kept by a plausible group of honest nodes, the method guarantees correctness in finite samples and produces smaller answer sets than simpler approaches. Experiments on medical exam question‑answering tasks with language‑model nodes demonstrate that the method meets the target coverage whenever the number of misbehaving nodes does not exceed the declared bound, while plain averaging often fails.

By Prasanjit Dubey, Aritra Guha, Xiaoming Huo
arXiv Machine Learning
Sep 16

SWB-DM: A Calibrated Sliced-Wasserstein-Barycenter Aggregator with Delayed-Momentum Caching for Byzantine-Robust Federated Learning under Partial Participation

The paper introduces SWB-DM, a Byzantine‑robust federated learning aggregator that treats each slice of a client update as a one‑dimensional distribution, computes a trimmed Wasserstein barycenter across clients, and uses a medoid‑based gauge‑fixing step to recover coordinate identity. It further incorporates delayed‑momentum caching to decouple robustness from the specific clients sampled each round. Extensive experiments on CIFAR‑10, CIFAR‑100, FEMNIST, and a 500‑client scalability run reveal distinct failure modes of existing defenses and demonstrate that SWB‑DM achieves significant gains, especially when compared under equal round budgets.

By Saranraj S, Saranya M S, Alex David S, Ajay Kumar A