Recent advances in information security requires strong keys which are randomly generated. Most of the keys are generated by the softwares which use software-based random number generators. However, implementing a True Random Number Generator (TRNG) without using a hardware-supported platform is not reliable. In this paper, a biometric authentication system using a FPGA-based TRNG to produce a private key that encrypts the face template of a person is presented. The designed hardware can easily be mounted on standard or embedded PC via its PCI interface to produce random number keys. Random numbers forming the private key is guaranteed to be true because it passes a two-level randomness test. The randomness test is evaluated first on the hardware then on the PC by applying the full NIST test suite. The whole system implements an AES-based encryption scheme to store the person's secret safely. Assigning a private key which is generated by our TRNG guarantees a unique and truly random password. The system stores the Wavelet Fourier-Mellin Transform (WFMT) based face features in a database with an index number that might be stored on a smart or glossary card. The objective of this study is to present a practical application integrating any biometric technology with a hardware-implemented TRNG.