securing ec communications  authentication system have five key elements. namely.  a person or group to be authenticated  a distinguishing characteristic that asides the person or the group apart  a proprietor responsible for the system being used  an authentication mechanism for verifying the presence of the differentiating characteristic  an access control mechanism ( a mechanism that limits the actions that can be perform by an authenticated person or group) for limiting the actions performed by the authenticated person or group . extruded acrylic tubing in a square shape is made by a continuous extrusion of the acrylic rod in an process that delivers beautiful clarity. they are cut on--line to 72""+. we can cut down to any length with the purchase of the full 6ft piece. if you need large quantities of a specific length, we can run these to size at the time that thickness is being extruded.