A computer-implemented method involves identifying an initial element for serving by a web server system to a client device and recoding the element by creating a plurality of different elements that each represent a portion of the initial element. The different elements are then served in place of the initial element. A response is received form the client device and has portions that correspond to the different elements, and a combined response is created by combining the received portions in a manner that corresponds to a manner in which the initial element was recoded to create the plurality of different elements.