Sparse Tokens Suffice: Jailbreaking Audio Language Models via Token-Aware Gradient Optimization

Fuente: arXiv
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Main Authors: Fang, Zheng, Wang, Xiaosen, Zhang, Shenyi, Wang, Shaokang, Ge, Zhijin
Format: Preprint
Published: 2026
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author Fang, Zheng
Wang, Xiaosen
Zhang, Shenyi
Wang, Shaokang
Ge, Zhijin
author_facet Fang, Zheng
Wang, Xiaosen
Zhang, Shenyi
Wang, Shaokang
Ge, Zhijin
contents Jailbreak attacks on audio language models (ALMs) optimize audio perturbations to elicit unsafe generations, and they typically update the entire waveform densely throughout optimization. In this work, we investigate the necessity of such dense optimization by analyzing the structure of token-aligned gradients in ALMs. We find that gradient energy is highly non-uniform across audio tokens, indicating that only a small subset of token-aligned audio regions dominates the optimization signal. Motivated by this observation, we propose Token-Aware Gradient Optimization (TAGO), which enables sparse jailbreak optimization by retaining only waveform gradients aligned with audio tokens that have high gradient energy, while masking the remaining gradients at each iteration. Across three ALMs, TAGO outperforms baselines, and substantial sparsification preserves strong attack success rates (e.g. on Qwen3-Omni, $\mathrm{ASR}_{l}$ remains at 86% with a token retention ratio of 0.25, compared to 87% with full token retention). These results demonstrate that dense waveform updates are largely redundant, and we advocate that future audio jailbreak and safety alignment research should further leverage this heterogeneous token-level gradient structure.
format Preprint
id arxiv_https___arxiv_org_abs_2605_04700
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Sparse Tokens Suffice: Jailbreaking Audio Language Models via Token-Aware Gradient Optimization
Fang, Zheng
Wang, Xiaosen
Zhang, Shenyi
Wang, Shaokang
Ge, Zhijin
Cryptography and Security
Artificial Intelligence
Computation and Language
Machine Learning
Sound
Jailbreak attacks on audio language models (ALMs) optimize audio perturbations to elicit unsafe generations, and they typically update the entire waveform densely throughout optimization. In this work, we investigate the necessity of such dense optimization by analyzing the structure of token-aligned gradients in ALMs. We find that gradient energy is highly non-uniform across audio tokens, indicating that only a small subset of token-aligned audio regions dominates the optimization signal. Motivated by this observation, we propose Token-Aware Gradient Optimization (TAGO), which enables sparse jailbreak optimization by retaining only waveform gradients aligned with audio tokens that have high gradient energy, while masking the remaining gradients at each iteration. Across three ALMs, TAGO outperforms baselines, and substantial sparsification preserves strong attack success rates (e.g. on Qwen3-Omni, $\mathrm{ASR}_{l}$ remains at 86% with a token retention ratio of 0.25, compared to 87% with full token retention). These results demonstrate that dense waveform updates are largely redundant, and we advocate that future audio jailbreak and safety alignment research should further leverage this heterogeneous token-level gradient structure.
title Sparse Tokens Suffice: Jailbreaking Audio Language Models via Token-Aware Gradient Optimization
topic Cryptography and Security
Artificial Intelligence
Computation and Language
Machine Learning
Sound
url https://arxiv.org/abs/2605.04700