A method and apparatus for an system and process for sharing a secret over an unsecured channel in conjunction with an authentication system. The mount includes an elastomeric upper mount and lower mount and a threaded fastener drawing the two elastomeric mounts together. In one embodiment, the \u03b2-sheet mimetic is a thrombin inhibitor. If it is determined that a macroblock is to be coded using spatial encoding, the macroblock is coded using the associated prediction mode. The calculation of the square root includes: calculating an approximated value of the square root, having a first precision, and then calculating a corrective value and combining said approximated value with said corrective value to obtain a square root value having a second precision greater than the first precision.