信息网络安全 ›› 2025, Vol. 25 ›› Issue (12): 1927-1935.doi: 10.3969/j.issn.1671-1122.2025.12.008

• 理论研究 • 上一篇    下一篇

基于对比学习的动态手写签名验证模型保护方法

付章杰1,2,3(), 陈天宇1,2,3, 崔琦1,2,3   

  1. 1.南京信息工程大学数字取证教育部工程研究中心,南京 210044
    2.南京信息工程大学计算机学院,南京 210044
    3.南京信息工程大学网络空间安全学院,南京 210044
  • 收稿日期:2025-10-10 出版日期:2025-12-10 发布日期:2026-01-06
  • 通讯作者: 付章杰 E-mail:fzj@nuist.edu.cn
  • 作者简介:付章杰(1983—),男,河南,教授,博士,CCF会员,主要研究方向为人工智能安全、深度伪造取证和区块链安全|陈天宇 (2001—),男,江苏,硕士研究生,主要研究方向为信息隐藏|崔琦(1994—),男,辽宁,副教授,博士,主要研究方向为信息隐藏、深度学习模型安全
  • 基金资助:
    国家自然科学基金(U22B2062);国家自然科学基金(62172232);国家自然科学基金(62402230);江苏省自然科学基金(BK20240693)

Dynamic Handwritten Signature Verification Models Protection Method Based on Contrastive Learning

FU Zhangjie1,2,3(), CHEN Tianyu1,2,3, CUI Qi1,2,3   

  1. 1. Engineering Research Center of Digital Forensics Ministry of Education, Nanjing University of Information Science and Technology, Nanjing 210044, China
    2. School of Computer Science, Nanjing University of Information Science and Technology, Nanjing 210044, China
    3. School of Cyberspace Security, Nanjing University of Information Science and Technology, Nanjing 210044, China
  • Received:2025-10-10 Online:2025-12-10 Published:2026-01-06
  • Contact: FU Zhangjie E-mail:fzj@nuist.edu.cn

摘要:

动态手写签名作为一种重要的身份验证手段,通常通过比对签名模板与待验证签名,并依据阈值判断真伪。然而,随着深度学习在手写签名验证中的广泛应用,模型规模与训练成本显著增加,且模型作为服务提供时,面临被非法调用或滥用的风险。为确保签名验证模型仅被授权用户使用,文章提出一种基于对比学习的动态手写签名模型保护方法。该方法通过构建含正确密钥的签名与原始签名,以及含正确密钥与含随机密钥签名之间的对比损失,联合优化密钥嵌入和签名验证模型,利用对比学习让模型与含正确密钥签名关联的同时,区分出原始签名和含随机密钥签名,使模型仅对包含正确密钥的签名保持验证能力,从而有效防止未经授权的访问;同时,该机制可实现模型所有权确认与知识产权追踪。基于大型动态签名数据集DeepSignDB的实验结果表明,在拥有4张签名模板并包含熟练伪造样本的条件下,含正确密钥签名等错误率从原模型的2.65%上升为4.40%,原始签名和含随机密钥签名分别上升至16.98%与16.51%,实现了在显著增强模型安全性和可追溯性的同时,仍能保持原有的签名验证性能。

关键词: 动态手写签名验证, 模型保护, 对比学习

Abstract:

Dynamic handwritten signatures, as an important means of identity verification, usually compare the signature template with the signature to be verified and determine its authenticity based on a threshold. However, with the wide application of deep learning in the verification of handwritten signatures, the scale of models and training costs have significantly increased. Moreover, when models are provided as services, they are at risk of being illegally invoked or abused. To ensure that the signature verification model was only used by authorized users, this paper proposed a dynamic handwritten signature model protection method based on contrastive learning. This method jointly optimized the key embedding and signature verification model by constructing the contrastive loss between the signature containing the correct key and the original signature, as well as between the signature containing the correct key and the signature containing the random key, so that the model only maintained the verification capability for the signature containing the correct key, thereby effectively preventing unauthorized access. Meanwhile, this mechanism could achieve the confirmation of model ownership and the tracking of intellectual property rights. The experimental results based on the large dynamic signature dataset DeepSignDB show that under the condition of having 4 signature templates and including skilled forgery samples, the equal error rate of signatures with correct keys increases from 2.65% of the original model to 4.40%, and the original signatures and signatures with random keys increase to 16.98% and 16.51% respectively. It has achieved a significant enhancement in model security and traceability while still maintaining the original signature verification performance.

Key words: dynamic handwritten signature verification, model protection, contrastive learning

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