Privacy protection based on binary fingerprint compression

This paper proposes a novel system to protect the fingerprint database based on compressed binary fingerprint images. In this system, the user can store private data with high capacity. First, the grayscale fingerprint image is transformed into a binary bitstream. Then, the binary bitstream is compressed using run-length encoding and Huffman encoding technique to create a sparse space to accommodate private data. Finally, the new image constructed by the obtained binary bitstream is encrypted with an encryption key. For fingerprint matching, it is only need to decrypt and decompress the encrypted image in the database to obtain the binary fingerprint image. When the matching is passed, the private data can be extracted to a user with data-embedding key. If the matching is failed, the private data cannot extracted for the purpose of privacy security. Even if a leakage of the encryption key occurs, this system can still protect the privacy data of the user due to the existence of the data-embedding key. Meanwhile, the encoding and decoding phases are real time, which guarantee the practicability of the proposed system.