A privacy-preserving biometric authentication protocol

Kok Seng Wong, Myung Ho Kim

Research output: Contribution to journalArticlepeer-review


Biometric-based authentication systems have been widely used in many applications that require high reliable scheme. However, the rapid deployment of biometric systems raises great attentions about the privacy concern. The primary concern in any biometric-based system is the leakage of user's biometric templates stored in the server. This is of particular important because biometric characteristics for humans are limited and they cannot be reissued or changed. Once the original template has been revealed, the user's privacy will be compromised. A malicious party might use the compromised template to gain unauthorized access to the system or for cross-matching purposes. One of the commonly used solutions for template protection is the encryption of the templates. Since the same biometric trait will not produce two identical feature vectors, the encryption of two slightly difference feature vectors will produce two distinct ciphertexts. Hence, encrypted templates must be decrypted before they can be used for comparison. Unfortunately, the decryption of encrypted templates is viewed as insecure because it is too risky to expose the original biometric template during the authentication process. We propose a privacy-preserving biometric authentication system which securely authenticates users and also protects their biometric features (both the query feature vector and template). We incorporate homomorphic encryption scheme which made the comparison possible in the encrypted domain. In our protocol, the similarity score (based on squared Euclidean distance) between the query feature vector and the biometric template is computed without the decryption of the original template. Our protocol fulfills the requirements of template protection and extra attention is paid to the advantages of using a homomorphic encryption scheme over biometric-based authentication systems. Finally, we show the correctness, security and privacy analysis of our protocol in this paper.

Original languageEnglish
Pages (from-to)683-688
Number of pages6
JournalAdvanced Science Letters
Publication statusPublished - Jul 2 2012
Externally publishedYes


  • Biometric template protection
  • Biometrics-based systems
  • Homomorphic encryption scheme
  • Privacy-preserving biometric authentication
  • Secure squared euclidean distance

ASJC Scopus subject areas

  • Health(social science)
  • Computer Science(all)
  • Education
  • Mathematics(all)
  • Environmental Science(all)
  • Engineering(all)
  • Energy(all)


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