An assembly for retaining a board such as a printed circuit board in the groove of a plate such as a cold plate. The method includes the step of registering a plurality of users and providing each of the users with respective public and private encryption keys. All of the physical systems are irradiated with light pulses resonant with |0>-|3> and |1>-|3>, and a phase of the light pulse resonant with the target system is shifted by a specific value dependent on a unitary transformation U. Independence between clusters is attained since the separate clustered functional unit register file segment pairs have local bypassing that allows internal computations to proceed, but have only limited bypassing between different functional unit register file segment pair clusters. Following wafer test the special test circuitry is electrically isolated from the functional circuitry and power supplies such that it does not load functional circuit signals nor consume power. In order to reduce a period comparison error, synchronization circuitry operates to synchronize the N divider of the PLL and an M divider of the coarse tuning circuit.