Biometric templates stored on Ingenico terminals are one‑way, encrypted representations of the original scan, so the raw fingerprint, palm‑vein pattern, facial image or iris data cannot be mathematically reversed or reconstructed from the template. The encryption keys reside in a tamper‑resistant hardware security module and the matching is performed locally, meaning the original biometric never leaves the device and cannot be extracted by an attacker. This design, combined with PCI‑DSS‑compliant end‑to‑end encryption and secure firmware, ensures that even if a terminal were compromised the stored biometric data would remain unrecoverable.