Systems and methods are provided for authorizing a user to access an access-controlled environment. The system includes a system server platform that communicates with fixed PC's, servers and mobile devices (e.g., smartphones) operated by users. The systems and methods described herein enable a series of operations whereby a user attempting to access an access-controlled environment is prompted to biometrically authenticate using the user's preregistered mobile device. Biometric authentication can include capturing images of the user's biometric features, encoding the features as a biometric identifier, comparing the biometric identifier to a previously generated biometric identifier and determining liveness. In addition, the authentication system can further authorize the user and electronically grant access to the access-controlled environment. In this manner the secure authentication system can, based on biometric authentication, authorize a user's access to devices, online services, physical locations or any networked environment that require user authorization.