Abstract: Biometric authentication is often considered to enhance identity verification. The use of biometrics also introduces new challenges to protect the privacy of the subjects while at the same time increasing the security of a verification system. In this paper, a set of requirements is proposed for biometric processing techniques to safeguard privacy and security. From these requirements, a reference architecture is derived that outlines processes and interfaces of biometric template protection methods in a high-level, technology-neutral way.