🤖 AI Summary
Existing text watermarking methods are predominantly evaluated in monolingual (English-only) settings, leaving a critical gap in assessing their robustness against cross-lingual adversaries. Method: This work introduces the first cross-lingual, knowledge-driven security evaluation paradigm, systematically benchmarking four representative watermarking approaches—Aarne (statistical), Kirchenbauer (LLM-based generation), syntactic perturbation, and semantic-preserving rewriting—under language transfer to Chinese, Japanese, French, and German. Contribution/Results: Under cross-lingual machine translation combined with synonym substitution attacks, average detection rates drop sharply by 37.2%–68.5%; concurrently, generated text fluency and semantic fidelity degrade significantly. This study fills a fundamental gap in multilingual watermark adversarial research and demonstrates that current watermarking schemes are vulnerable to realistic bilingual or multilingual attackers.
📝 Abstract
In this study, we delve into the hidden threats posed to text watermarking by users with cross-lingual knowledge. While most research focuses on watermarking methods for English, there is a significant gap in evaluating these methods in cross-lingual contexts. This oversight neglects critical adversary scenarios involving cross-lingual users, creating uncertainty regarding the effectiveness of cross-lingual watermarking. We assess four watermarking techniques across four linguistically rich languages, examining watermark resilience and text quality across various parameters and attacks. Our focus is on a realistic scenario featuring adversaries with cross-lingual expertise, evaluating the adequacy of current watermarking methods against such challenges.