One embodiment of the invention provides a technique for generating a plurality modified copies of a source file. This method may include generating each respective modified copy by determining an initial, unmodified portion of the modified copy. The initial, unmodified portion is set to a first point in the source file in a first modified copy and incremented by a specified amount for each successive modified copy, up to a second point in the source file. Generating each respective modifed copy also includes following the initial unmodified portion, generating an alternating sequence of modified and unmodified portions, based on a fixed modification size, until reaching an end point in the source file.
Another embodiment of the invention includes a method of disrupting a file sharing service. This method may generally include generating a plurality of modified copies of a source file. Each modified copy includes an initial, unmodified portion of a distinct size, followed by an alternating sequence of modified and unmodified portions of the modified copy based on the modification size, until reaching an end point, and each modified copy also shares at least one region of modified.