Heuristic Authorship Obfuscation
Janek Bevendorff, Martin Potthast, Matthias Hagen, Benno Stein · 2019
Authorship verification is the task of determining whether or not two texts were written by the same author.This paper deals with the adversary task, called authorship obfuscation: Preventing verification by altering a tobe-obfuscated text.We introduce an approach that (1) models writing style difference as the Jensen-Shannon distance between the character n-gram distributions of texts, and (2) manipulates an author's subconsciously encoded writing style in a sophisticated manner using heuristic search.To obfuscate, we explore the huge space of textual variants in order to find a paraphrased version of the to-be-obfuscated text that has a sufficient Jensen-Shannon distance at minimal costs in terms of text quality loss.We analyze, quantify, and illustrate the rationale of this approach, define paraphrasing operators, derive obfuscation thresholds, and develop an effective obfuscation framework.Our authorship obfuscation approach defeats state-of-the-art verification approaches, including unmasking and compression models, while keeping text changes at a minimum.