A two-level authentication system is described supporting two-factor authentication that offers efficient protection for secure on-line web transactions. It includes a global unique identity (UID) provided either by an institute-issued/personal trusted device, or based on client computing platform hardware attributes, and generated using institution authorized private software, institution-authorized authentication proxy software, and an institution-generated credential code which is pre-stored in the token and only accessible by the institute-authorized authentication proxy software. The institution-authorized authentication proxy software uses the user's PIN and the trusted device's UID as input and verifies the user and device identities through institution-generated credential code which was pre-stored in the trusted device. Authentication is performed in two levels: the first authenticates the user and the trusted device locally; and the second authenticates the user remotely at the institution-owned authentication server. Various embodiments add extra levels of security, including one-time-password management.