SafetySecurityTrustworthinesscs.CL
Fundamental Limitations of Alignment in Large Language Models
Yotam Wolf, Noam Wies, Oshri Avnery, Yoav Levine, Amnon Shashua
April 19, 2023
International Conference on Machine Learning
216 citations
7 influential
Key Takeaways
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No alignment method is completely foolproof: The paper proves that if an undesired behavior has any probability of occurring in a language model, adversarial prompts can be crafted to trigger it—and the longer the prompt, the higher the likelihood of success. This means alignment techniques that reduce harmful outputs without eliminating them entirely remain vulnerable to attack.
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Current popular alignment methods have inherent weaknesses: The research identifies a fundamental mechanism in leading alignment approaches like reinforcement learning from human feedback (RLHF) that makes models susceptible to adversarial manipulation, explaining why techniques used by companies like OpenAI can still be "jailbroken" through clever prompting.
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Adversarial jailbreaks are not just engineering problems: The paper provides theoretical backing for real-world phenomena like "ChatGPT jailbreaks," where users trick AI systems into adopting harmful personas. These aren't bugs to be patched—they reflect fundamental mathematical limitations of how alignment currently works.
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Complete removal of behaviors may be necessary for safety: Rather than simply reducing the probability of harmful outputs, the theoretical framework suggests that truly safe AI systems may need to completely eliminate undesired behaviors rather than merely attenuate them, which presents a significant technical challenge.
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The alignment problem is harder than previously understood: These findings expose that alignment has inherent limitations that go beyond current implementation challenges, suggesting the AI safety community may need to reconsider fundamental approaches to making language models safe and trustworthy.
Abstract
An important aspect in developing language models that interact with humans is aligning their behavior to be useful and unharmful for their human users. This is usually achieved by tuning the model in a way that enhances desired behaviors and inhibits undesired ones, a process referred to as alignment. In this paper, we propose a theoretical approach called Behavior Expectation Bounds (BEB) which allows us to formally investigate several inherent characteristics and limitations of alignment in large language models. Importantly, we prove that within the limits of this framework, for any behavior that has a finite probability of being exhibited by the model, there exist prompts that can trigger the model into outputting this behavior, with probability that increases with the length of the prompt. This implies that any alignment process that attenuates an undesired behavior but does not remove it altogether, is not safe against adversarial prompting attacks. Furthermore, our framework hints at the mechanism by which leading alignment approaches such as reinforcement learning from human feedback make the LLM prone to being prompted into the undesired behaviors. This theoretical result is being experimentally demonstrated in large scale by the so called contemporary "chatGPT jailbreaks", where adversarial users trick the LLM into breaking its alignment guardrails by triggering it into acting as a malicious persona. Our results expose fundamental limitations in alignment of LLMs and bring to the forefront the need to devise reliable mechanisms for ensuring AI safety.
Paper Info
arXiv ID2304.11082
PublishedApril 19, 2023
RevisedJune 3, 2024
Citations
216
Influential
7
Relevance92%
VenueInternational Conference on Machine Learning
TypeJournalArticle, Conference
Categorycs.CL
Responsible AI Topics
SafetySecurityTrustworthiness
Links
Citation data from Semantic Scholar