A large-scale attendance, productivity, activity and availability biometric control method using the telephone network, for individual client users with speaker verification technology based on limited enrolling data and short verification sentences. More particularly, each of the spatial light modulators may be a liquid crystal display, an electrochromic device, a micromirror array, a microlouvre array, an electro-optic device, or a holographic device. On a receive side, a receiving communication device receives the transmitted, encrypted symbols and provides decryption at a physical layer by shifting a phase of each encrypted symbol in correspondence with the phase used to encrypt the symbol at the transmit side. The present invention can not only secure communication via the data communication interface, but also allow the operating system to handle normally and stably an interrupt, so as to reduce the system power consumption. The wedge is shaped so that upon a reduction or cessation of the horizontally acting force the stress member, remains in the resiliently deformed state in which it draws the adapter and the lip towards each other and keeps them immovably secured to each other until the wedge can be withdrawn following a repressurization of the hydraulic actuator.