Secure protocols for external-facing authentication are provided for both user templates stored on their devices and the biometric measurement captured by external sensors of an access device. The protocols provide different levels of security, ranging from passive security with some leakage to active security with no leakage. A packing technique is also provided. Zero-knowledge techniques are used during enrollment to validate a norm of user templates and knowledge of the plaintext biometric template. One enrolled, the verifier can sign the encrypted template for use in a later matching phase with an access device.