Privacy protection of fingerprint database using lossless data hiding

In this paper, we introduce a fingerprint authentication system for protecting the privacy of the fingerprint template stored in a database. The template, which is a binary fingerprint image after thinning, will be embedded with private personal data in the user enrollment phase. In the user authentication phase, these hidden personal data can be extracted from the stored template for verifying the authenticity of the person who provides the query fingerprint. A novel lossless data hiding scheme is proposed for a thinned fingerprint. By adopting “embeddability criterion”, data is hidden into the template by just adding some boundary pixels in the template. These boundary pixels can be extracted and removed to reconstruct the original thinned fingerprint so that fingerprint matching accuracy is not affected. Compared with using existing binary image data hiding techniques, our scheme has a better performance for a thinned fingerprint.