1. A computer-implemented method comprising: obtaining, at a computer system, a first content item from an online source, wherein the first content item is obtained via network connection; generating a characterizing signature of the first content item, by: selecting a quantity of text for analysis, the first content item comprising the quantity of text; eliminating filler words from the quantity of text to identify a plurality of significant words; arranging a predetermined number of the plurality of significant words from the quantity of text to create a document key; applying a hash function to the document key to obtain a hashed document key; and appending a language identifier to the hashed document key to create the characterizing signature; finding a previously-saved instance of the characterizing signature in a cache memory architecture of the computer system; retrieving, from the cache memory architecture, data associated with a second content item, in response to finding the previously-saved instance of the characterizing signature, wherein the second content item is characterized by the characterizing signature; analyzing the data associated with the second content item, corresponding data associated with the first content item, and decision criteria; and identifying either the first content item or the second content item as an original content item, based on the analyzing.