更高效的指纹生物特征加密

More Efficient Fingerprint Biometric Encryption

随着生物特征识别技术应用的愈加深入,生物特征所涉及到的人的隐私以及由此带来的安全性问题逐渐暴露出来.生物特征加密结合了生物识别技术和加密技术,将生物特征和密钥融合,使得密钥和生物特征本身都很难从系统存储的模板中获取,当且仅当活体生物特征提交给系统时密钥才会重新生成.生物特征加密的天然模糊性必然要求相应的加密技术具备容错性,基于模糊身份的公钥加密可自然用于生物特征加密.为弥补直接使用模糊身份加密造成的开销大的不足,也为了更精确的进行指纹识别,本文从模糊身份加密出发,构造了一个标准模型下新的自适应安全的模糊身份加密算法,并在此基础上借助密钥共享算法构造了双阈值的指纹生物特征加密方案.与已有的指纹加密方案相比,本文提出的方案不仅在开销上优于直接使用模糊身份加密的指纹加密,还能分别从全局与局部两方面完成指纹的识别与加密,使得方案更具实用性.同时经过数学证明,本文提出的加密方案在标准模型下是自适应安全的.

With the rapid development of biometric identification techniques,some severe problems gradually emerged due to its inherent disadvantages,primarily the security issues brought about by the privacy exposure from each individual's biometric.Biometric encryption schemes consider the biometric as a secret key,so that either the key or the biometric must be computationally difficult to retrieve from the stored BE template and the key will be recreated only if the genuine biometric sample passed the verification.The encryption process should have some tolerance because of the natural variability of the biometrics,hence fuzzy identity-based encryption(FIBE)can be used for biometric encryption.To reduce the cost and make the identification more precise than the direct use of fuzzy identity encryption,this paper proposes a new fuzzy identity encryption algorithm based on such a traditional algorithm.Then a dual-threshold fingerprint-based biometric encryption scheme is constructed by using secret sharing algorithm.Compared with some existing schemes,the overhead of the proposed scheme is better than the direct use of fuzzy identity encryption.Furthermore,the proposed scheme completes the identification and encryption of the fingerprints from both global and local part,making the scheme more practical.Moreover,our scheme is proved to have adaptive security under the standard model.