指纹特征加密是生物特征识别技术中最为活跃的研究领域之一。然而指纹特征是人体固有的特征,具有唯一性与终身不变性,一旦识别系统中的用户指纹模板丢失,将是永久性的。为了避免用户指纹模板丢失,基于巴特沃斯低通滤波器原型,设计了一组不可逆转换函数,将用户原始指纹模板转换为可撤销指纹模板,不同识别系统中存储的可撤销指纹模板具有互异性与不可逆性,进而有效规避原始指纹模板的不变性与公开性所带来的安全隐患。匹配精度、不可逆性、转换速度等方面的实验分析表明,所构造可撤销指纹模板方案在认证效率、安全性、计算效率等方面具有良好性能。

Fingerprint encryption is one of the most active research domains in biometrics recognition. However, fingerprints are human inherent characteristics, which are associated with one person permanently and cannot be changed. Once one fingerprint template is compromised, it is permanent. In order to avoid the loss of fingerprint templates, a set of irreversible transform functions, which are based on the Butterworth Low Pass Filter, are proposed. They transfer the original fingerprint templates to cancelable fingerprint templates. Those cancelable templates,stored in different recognition system, are different and irreversible, which can overcome the security limitations caused by the invariance and openness of the fingerprint templates. Experiments regarding matching precision, irreversibility and transform efficiency show that this scheme has high performance on authentication, security and computation.