arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2509.23286cs.CLcs.AI

A2D: 任意顺序、任意步长的安全对齐用于扩散语言模型

A2D: Any-Order, Any-Step Safety Alignment for Diffusion Language Models

Department of Artificial Intelligence, Yonsei University(人工智能系,延世大学);Department of Computer Science and Engineering, Yonsei University(计算机科学与工程系,延世大学)

Wonje Jeung, Sangyeon Yoon, Yoonjun Cho, Dongjae Jeon, Sangwoo Shin, Hyesoo Hong, Albert No

AI总结:

A2D通过令牌级对齐方法,在扩散语言模型中实现任意顺序和步长攻击的鲁棒防御,显著降低有害输出生成概率并提升安全终止效率。

摘要:

扩散大语言模型(dLLMs)能够实现任意顺序的生成,但这种灵活性扩大了攻击面:有害内容可能出现在任意位置,且基于模板的预填充攻击如DIJA绕过响应级拒绝。我们引入A2D(任意顺序、任意步长防御),一种基于令牌的对齐方法,使dLLMs在出现有害内容时能够发出[EOS]拒绝信号。通过在随机掩码下直接在令牌级别对齐安全性,A2D在各种条件下都对任意解码顺序和任意步长预填充攻击具有鲁棒性。它还实现了实时监控:dLLMs可能开始响应,但若出现不安全的延续会自动终止。在安全性基准测试中,A2D一致阻止生成有害输出,将DIJA的成功率从超过80%降至几乎零(在LLaDA-8B-Instruct上为1.3%,在Dream-v0-Instruct-7B上为0.0%),并且阈值化的[EOS]概率允许早期拒绝,使安全终止速度提升高达19.3倍。

英文摘要:

Diffusion large language models (dLLMs) enable any-order generation, but this flexibility enlarges the attack surface: harmful spans may appear at arbitrary positions, and template-based prefilling attacks such as DIJA bypass response-level refusals. We introduce A2D (Any-Order, Any-Step Defense), a token-level alignment method that aligns dLLMs to emit an [EOS] refusal signal whenever harmful content arises. By aligning safety directly at the token-level under randomized masking, A2D achieves robustness to both any-decoding-order and any-step prefilling attacks under various conditions. It also enables real-time monitoring: dLLMs may begin a response but automatically terminate if unsafe continuation emerges. On safety benchmarks, A2D consistently prevents the generation of harmful outputs, slashing DIJA success rates from over 80% to near-zero (1.3% on LLaDA-8B-Instruct, 0.0% on Dream-v0-Instruct-7B), and thresholded [EOS] probabilities allow early rejection, yielding up to 19.3x faster safe termination.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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