Biometric hash generation and user authentication based on handwriting using secure sketches

Contrary to cryptographic hash functions, which calculate the same value for only the same input, biometric hash functions have to generate identical hashes from varying input data of the same person. In this paper a secure sketch method is suggested that was developed to generate hash values from dynamic handwritten data. The presented secure sketch method is motivated by the framework suggested by Dodis et al. (2004) and the face based secure sketch algorithm of Sutcu et al. (2007). The results of the proposed method are compared to those of another biometric hashing algorithm from recent work of the authors as reference algorithm. On one side the evaluation results showing a very promising performance of the secure sketch method in case of reproducibility (best result 96%) and collision probability (best result 3%). Compared to the reference algorithm this results corresponds to an improvement of approx. 20% for reproducibility and approx. 45% for collision probability based on the same test setup. On the other side the verification performance of the reference algorithm, measured by EER, is higher than for the secure sketch method. While the reference algorithm determines an EER of 0.0233 in the best case, the secure sketch method calculates an EER of 0.0559.