Lucas Ballard Seny Kamara Michael K. Reiter The Practical Subtleties of Biometric Key Generation. 61-74 2008 USENIX Security Symposium http://www.usenix.org/events/sec08/tech/full_papers/ballard/ballard.pdf conf/uss/2008 db/conf/uss/uss2008.html#BallardKR08