journal article·2025-11-27Open access

CoFT: A Fair and Transparent Compensation Framework for Hierarchical Federated Learning

Siwan Noh, Sang Uk Shin, Kyung-Hyune Rhee

Applied Sciences· Volume 15· Issue 23

Abstract

Hierarchical Federated Learning (HFL) requires a scalable and transparent incentive mechanism, yet existing on-chain approaches are too costly and centralized solutions lack trust. To address this, we propose CoFT, a hybrid framework that manages rewards off-chain using a hierarchy of state channels and a stablecoin while securing the system’s integrity with a single on-chain cryptographic anchor. This architecture dramatically reduces on-chain complexity from a prohibitive O(N×T) to a sustainable O(I+S+N), enabling cryptographic verifiability, automated trustless payouts, and fair burden-sharing. CoFT thus offers a robust and economically viable blueprint for the financial infrastructure of large-scale, trustworthy collaborative AI ecosystems.
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Research context

OpenAlex topics: Cryptography and Data Security · Privacy-Preserving Technologies in Data · Blockchain Technology Applications and Security

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Blockchain Technology R&D Laboratory, Department of Game Engineering, Dong-Eui University, Busan 47340, Republic of Korea

Division of Computer Engineering and Artificial Intelligence, Pukyong National University, Busan 48513, Republic of Korea

The Industrial Science Technology Research Institute, Pukyong National University, Busan 48513, Republic of Korea

Funding

’Technology Commercialization Collaboration Platform Construction’ project of the INNOPOLIS FOUNDATION · IITP (Institute of Information & Communications Technology Planning & Evaluation)-ITRC

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