FedACK: Federated Adversarial Contrastive Knowledge Distillation for Cross-Lingual and Cross-Model Social Bot Detection

Abstract

Social bot detection is of paramount importance to the resilience and security of online social platforms. The state-of-the-art detection models are siloed and have largely overlooked a variety of data characteristics from multiple cross-lingual platforms. Meanwhile, the heterogeneity of data distribution and model architecture make it intricate to devise an efficient cross-platform and cross-model detection framework. In this paper, we propose FedACK, a new federated adversarial contrastive knowledge distillation framework for social bot detection. We devise a GAN-based federated knowledge distillation mechanism for efficiently transferring knowledge of data distribution among clients. In particular, a global generator is used to extract the knowledge of global data distribution and distill it into each client's local model. We leverage local discriminator to enable customized model design and use local generator for data enhancement with hard-to-decide samples. Local training is conducted as multi-stage adversarial and contrastive learning to enable consistent feature spaces among clients and to constrain the optimization direction of local models, reducing the divergences between local and global models. Experiments demonstrate that FedACK outperforms the state-of-the-art approaches in terms of accuracy, communication efficiency, and feature space consistency. CCS CONCEPTS• Computing methodologies → Adversarial learning; Machine learning.

Emerging Trends in Federated Learning: From Model Fusion to Federated X Learning

“…Wu et al [70] specifically designed an algorithm tailored for multi-access edge computing in a real-world scenario, leveraging knowledge distillation as a key component. FedACK [68] applies knowledge distillation in the cross-lingual social bot detection domain, showcasing a novel application that combines knowledge distillation and federated learning. This application demonstrates the potential for knowledge distillation to inspire more useful applications within this emerging field.…”