Toward Evasion-Resistant LLM Attribution with Multi-Scale Watermarking and Cryptographic Verification

Abstract

Large language models (LLMs) have transformed natural language generation capabilities across numerous applications, yet their proliferation raises critical concerns regarding content attribution, intellectual property protection, and potential misuse. Watermarking techniques have emerged as promising solutions for embedding verifiable signals into LLM outputs, but existing approaches remain vulnerable to sophisticated evasion attacks that exploit detection mechanisms through adversarial modifications. This paper introduces a novel watermarking framework that integrates multi-scale semantic embedding with cryptographic verification to achieve robust attribution of LLM-generated text. Our approach operates across multiple granularity levels, from token-level perturbations to discourse-level structural patterns, while incorporating error-correcting codes and cryptographic signatures to ensure detection integrity even under aggressive tampering attempts. Through comprehensive evaluation on diverse text generation tasks, we demonstrate that our framework achieves superior robustness against paraphrasing attacks, token substitution, and deletion operations while maintaining high text quality with perplexity comparable to unwatermarked outputs. The integration of cryptographic primitives enables public verifiability without exposing watermarking keys, addressing critical security requirements for real-world deployment. Our results show detection accuracy exceeding 94 percent under various attack scenarios while preserving semantic coherence and stylistic naturalness of generated text.