More and more applications rely on biometrics to authenticate or identify physical persons. Biometric data are intrinsically sensitive and vulnerable in today's applications:38 if they are stolen, their owners have currently no choice but to revoke them (where possible) to avoid future fraudulent use. In doing so, they lose all advantages linked to this biometric in terms of convenience and security.
We present the general ideas of biometric pseudonyms, followed by a short presentation of the basic ideas of a technique which allows developing biometric pseudonyms - using the example of iris recognition - in order to overcome major threats for security, privacy and convenience in today's use of biometrics. The present approach has been studied in the BioCrypt project, which led to a patent in 2009.