Combining DWT and LSB watermarking to secure revocable iris templates

In this paper, we present a scheme for securing revocable iris templates using watermarking. A user specific shuffling key is used to shuffle blocks of the iris code to achieve revocability, as well as increase the separation between genuine and imposter Hamming distance distributions. 3-level DWT decomposition is used for the watermarking algorithm. Discrete Wavelet Transform was chosen, for robustness, security and accuracy, to embed the shuffled iris code in a cover image. To test the proposed algorithm, recognition rates are calculated after several geometrical and frequency attacks, which shows acceptable performance rates, while ensuring revocability and security of the iris templates.