基于人脸特征密钥生成的身份认证系统

A face based key generation scheme for authentication

为了解决现有密钥生成方法存在伪接受率FAR和伪拒绝率FRR过大的不足,提出一种全新高效的人脸特征密钥生成方法,并将其应用于身份认证。在注册阶段,首先采用主成分分析(PCA)特征提取技术产生128维生物特征,再采用生物哈希的方法将128维PCA特征二值化;最后对128位序列采用统计最优的方法生成稳定的64位密钥和查询表。通过采用统计最优方法可以有效地降低FAR和FRR。在认证阶段,采用相同的特征提取和二值化方法对人脸图像进行处理,再通过查询表生成64位待识别人脸的密钥,并对其进行纠错编码生成最终的密钥,将最终密钥与模板库密钥进行比对,实现身份认证。采用ORL人脸库进行试验,得到的错误接受率FAR和错误拒绝率FRR分别为0和6.5%。

With biometric technology widely used, a key generation scheme based on face biometrics emerges. We proposea key generation scheme based on face biometrics and apply it in authentication. In order to decrease false accept rate （FAR） and false rejection rate （FRR）, biohashing and statistically optimal algorithm are chosen to generate the key. In enrollment stage, a 128-dimensional principal component analysis （PCA） feature vector is firstly extracted fi＇om the face image. And a biohashing process is utilized to improve the security and control the intra-class variations of biometric data to the minimal level. From the binary vector of 128 bits we select the statistically distinguishable 64 bits to form bio-key. Furthermore, an error-correct-code （ECC） is generated using Reed-Solomon algorithm. In authentication stage, the same procedure is implemented to extract PCA features and randomize the feature vectors. Then a bio-key is generated using the look-up table and auxiliary code. The authentication mainly relies on checking the validity of the bio-key. The experimental results using ORL face database shows that our algorithm is more effective. And when FAR is 0, the corresponding FRR of our approach is6.5%