Emoti-Attack: Zero-Perturbation Adversarial Attacks on NLP Systems via Emoji Sequences

TL;DR

This paper introduces Emoji-Attack, a novel adversarial attack method on NLP models that manipulates emojis to create subtle perturbations, revealing vulnerabilities with minimal perceptibility and high effectiveness.

Contribution

The paper presents a new emoji-based adversarial attack technique that is more efficient and less perceptible than previous text attack methods, expanding the scope of adversarial strategies in NLP.

Findings

Emoji-Attack achieves high success rates on various NLP models.

The method requires fewer queries than traditional attacks.

It maintains semantic similarity while perturbing emojis.

Abstract

Deep neural networks (DNNs) have achieved remarkable success in the field of natural language processing (NLP), leading to widely recognized applications such as ChatGPT. However, the vulnerability of these models to adversarial attacks remains a significant concern. Unlike continuous domains like images, text exists in a discrete space, making even minor alterations at the sentence, word, or character level easily perceptible to humans. This inherent discreteness also complicates the use of conventional optimization techniques, as text is non-differentiable. Previous research on adversarial attacks in text has focused on character-level, word-level, sentence-level, and multi-level approaches, all of which suffer from inefficiency or perceptibility issues due to the need for multiple queries or significant semantic shifts. In this work, we introduce a novel adversarial attack method, Emoji-Attack, which leverages the manipulation of emojis to create subtle, yet effective, perturbations. Unlike character- and word-level strategies, Emoji-Attack targets emojis as a distinct layer of attack, resulting in less noticeable changes with minimal disruption to the text. This approach has been largely unexplored in previous research, which typically focuses on emoji insertion as an extension of character-level attacks. Our experiments demonstrate that Emoji-Attack achieves strong attack performance on both large and small models, making it a promising technique for enhancing adversarial robustness in NLP systems.