A script is scanned to detect character strings that match predetermined criteria. The detected character strings are sorted in order of their appearance frequency and are associated with substitute characters or character strings such that a character string having a greater appearance frequency than another character string is associated with substitute characters or character string having a same or smaller number of characters. The script is searched for a given character string, and the given character string is replaced with its associated substitute characters or character strings. The content is unidirectionally distributed whereby the plurality of character strings is not distributed.