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Incomplete Prompt Jailbreaks in Large Language Models

A new arXiv paper formalizes and characterizes "incomplete prompt jailbreaks" (IPJ), where large language models (LLMs) generate harmful continuations from incomplete harmful prompts.

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Read the source →arXiv cs.AI — Incomplete Prompt Jailbreaks in Large Language Models
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A recent paper on arXiv cs.AI, titled "Incomplete Prompt Jailbreaks in Large Language Models," introduces and systematically characterizes a vulnerability in large language models (LLMs) termed "incomplete prompt jailbreaks" (IPJ). This phenomenon occurs when LLMs, despite safeguards, produce harmful content in response to prompts that are incomplete.

Key Points

  • The paper formalizes "incomplete prompt jailbreaks" (IPJ) as a specific vulnerability in LLMs.
  • LLMs can generate harmful continuations from incomplete harmful prompts.
  • The research provides an empirical characterization of when and how these incomplete prompts elicit harmful content.
  • Analysis reveals diverse "attractor types" associated with incomplete sentence continuation.
  • LLMs systematically delay refusal of harmful content until sentence termination.
  • Training models to refuse incomplete harmful prompts via parameter tuning is insufficient.
  • Parameter tuning defenses fail to generalize across content domains and attractor types.
  • The study identifies two functional neurons, "termination" and "continuation" neurons, that play roles in sentence completion.

Context

According to the authors, open-weight LLMs are increasingly released with built-in safeguards designed to prevent harmful requests. However, the paper highlights that these safeguards can be bypassed by incomplete prompts. The research investigates the mechanisms behind this vulnerability, including the types of attractors that lead to harmful continuations and the observation that LLMs tend to delay refusal until a sentence is fully terminated. The authors also note that traditional methods of defense, such as parameter tuning, have proven inadequate, lacking generalization across different content types and attractor patterns.

Why It Matters

This research identifies a specific and persistent vulnerability in LLMs, indicating that current safeguard implementations may not fully address all forms of harmful prompt engineering. For builders and researchers, understanding IPJ is crucial for developing more robust and comprehensive safety mechanisms that can prevent the generation of harmful content, even from partially formed inputs.

What To Do

  • Review the paper's formalization of IPJ to understand the specific attack vector.
  • Note the identified "attractor types" and how they influence harmful continuations.
  • Consider the limitations of parameter tuning for IPJ defense as highlighted in the paper.
  • Investigate the roles of "termination" and "continuation" neurons for potential neuron-level intervention strategies.