Journal of Computer Applications ›› 2026, Vol. 46 ›› Issue (2): 458-466.DOI: 10.11772/j.issn.1001-9081.2025020216

• Cyber security • Previous Articles    

Neighborhood-enhanced unsupervised graph anomaly detection

Limei DONG1,2, Yanzi LI1,2, Jiayin LI1,2, Li XU1,2()   

  1. 1.College of Computer and Cyber Security,Fujian Normal University,Fuzhou Fujian 350117,China
    2.Fujian Provincial Key Laboratory of Network Security and Cryptology,Fuzhou Fujian 350117,China
  • Received:2025-03-06 Revised:2025-04-27 Accepted:2025-05-07 Online:2025-05-16 Published:2026-02-10
  • Contact: Li XU
  • About author:DONG Limei, born in 2001, M. S. candidate. Her research interests include anomaly detection, network and information security.
    LI Yanzi, born in 1998, Ph. D. candidate. Her research interests include privacy protection, network and information security.
    LI Jiayin, born in 1990, Ph.D., lecturer. His research interests include artificial intelligence security, internet of vehicles security, privacy protection, machine learning.
    XU Li, born in 1970, Ph. D., professor. His research interests include network and information security, big data and informatization, mobile social networks, intelligent information processing. Email:xuli@fjnu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(62471139);Central Government Guided Local Science and Technology Development Special Program(2023L3007);Fujian Provincial Natural Science Foundation(2023J05128);Fujian Provincial Science and Technology Project(2022G02003)

基于邻域增强的无监督图异常检测

董莉梅1,2, 李雁姿1,2, 李家印1,2, 许力1,2()   

  1. 1.福建师范大学 计算机与网络空间安全学院,福州 350117
    2.福建省网络安全与密码技术重点实验室,福州 350117
  • 通讯作者: 许力
  • 作者简介:董莉梅(2001—),女,四川达州人,硕士研究生,主要研究方向:异常检测、网络与信息安全
    李雁姿(1998—),女,山东聊城人,博士研究生,主要研究方向:隐私保护、网络与信息安全
    李家印(1990—),男,山东梁山人,讲师,博士,主要研究方向:人工智能安全、车联网安全、隐私保护、机器学习
    许力(1970—),男,福建福州人,教授,博士,CCF会员,主要研究方向:网络与信息安全、大数据与信息化、移动社会网络、智能信息处理。 Email:xuli@fjnu.edu.cn
  • 基金资助:
    国家自然科学基金资助项目(62471139);中央引导地方科技发展专项(2023L3007);福建省自然科学基金资助项目(2023J05128);福建省科技项目(2022G02003)

Abstract:

To address the issue of unreliable neighborhood information due to the presence of anomalies, an efficient unsupervised graph anomaly detection method was proposed. In this method, a neighborhood enhancement strategy was utilized to construct multi-type neighborhood sets for central nodes, thereby capturing high-quality node representations and obtaining accurate self-neighborhood similarity. Firstly, an information extraction module based on dynamic neighborhood enhancement was optimized to select the optimal neighborhood strategy adaptively, thereby overcoming the feature homogeneity limitation of traditional fixed neighborhood selection methods during information extraction. Secondly, in order to reduce the interference of redundant information of the nodes during node feature fusion, an anonymous message passing scheme was proposed. In this scheme, features of the nodes were isolated, and neighborhood information was focused on solely, thereby enhancing the quality of message aggregation. Finally, an adaptive weighted anomaly scoring module was designed, using the distance between nodes as an evaluation scale to obtain node anomaly scores, thereby refining the anomaly detection results. Experimental results on five datasets demonstrate that the proposed method outperforms mainstream method CoLA (Anomaly detection on attributed networks via Contrastive self-supervised Learning) in detecting anomalies in complex graph structure, achieving an at least 8.0% AUPRC (Area Under the Precision-Recall Curve) improvement in identifying anomalous samples.

Key words: anomaly detection, unsupervised learning, contrastive learning, neighborhood selection, graph data

摘要:

针对异常的存在导致节点邻域信息不可靠的问题,提出一种高效的无监督图异常检测方法。该方法借助邻域增强策略构建多类型的中心节点的邻域集合,捕捉高质量的节点表示,并获取高准确度的自邻相似度。首先,通过优化一个基于动态邻域增强的信息提取模块,自适应地选择最优邻域策略,从而克服传统固定邻域选择方法在信息提取过程中特征单一的局限性;其次,为了降低节点特征融合时自身冗余信息的干扰,提出一种匿名消息传递方案,该方案能够隔离节点自身特征,只专注于邻域信息,从而提高消息聚合的质量;最后,通过设计一种自适应的加权异常评分模块,以节点之间距离作为评估尺度来获取节点的异常度,从而细化异常检测结果。在5个数据集上的实验结果表明,所提方法在应对复杂图结构的异常检测方面的表现优于现有主流方法CoLA(Anomaly detection on attributed networks via Contrastive self-supervised Learning),其中对异常样本的识别能力指标——AUPRC(Area Under the Precision-Recall Curve)至少提升了8.0%。

关键词: 异常检测, 无监督学习, 对比学习, 邻域选择, 图数据

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