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PAIR Attack

Original Paper

Chao, P., Robey, A., Dobriban, E., Hassani, H., Pappas, G. J., & Wong, E. (2023). Jailbreaking Black Box Large Language Models in Twenty Queries. arXiv:2310.08419. https://arxiv.org/abs/2310.08419

PAIR (Prompt Automatic Iterative Refinement) uses one LLM as an automated attacker that iteratively refines jailbreak prompts against a target model, guided by a judge model that scores each attempt.

How PAIR Works

sequenceDiagram
    participant A as Attacker LLM
    participant T as Target LLM
    participant J as Judge LLM

    loop Until success or max iterations
        A->>T: Send jailbreak candidate
        T->>A: Target response
        A->>J: (candidate, response)
        J-->>A: Score 1–10 + feedback
        A->>A: Refine candidate using feedback
    end
  1. The attacker LLM generates an initial jailbreak prompt from the goal.
  2. The target LLM responds.
  3. The judge LLM scores the response (1 = clearly refused, 10 = fully compliant harmful).
  4. If score ≥ threshold → attack success. Otherwise, the attacker refines based on judge feedback.
  5. Repeat up to max_iterations (default: 5).

Benchmark Results

In the strict PAIR mini-benchmark (4 core models, no defenses):

Model MIR Avg QTJ
Llama-3.3-70B 83.7% ~3.0
DeepSeek-R1-70B 83.2% ~3.0
DeepSeek-R1-14B 75.4% ~2.6
DeepSeek-V3.2 66.0% ~2.2

MIR by Model

Configuration

attacks:
  - pair

models:
  attack_model: genai:llama3.3:70b    # attacker LLM
  target_model: genai:deepseek-r1:14b # target LLM
  judge_model:  genai:llama3.3:70b    # judge LLM

attack_config:
  pair:
    max_iterations: 5
    judge_threshold: 8

Implementation Notes

  • Implemented in attacks/pair.py
  • Judge prompt uses a structured scoring rubric (1–10) with explicit feedback extraction
  • fusion_strategy field in output is set to pair_standalone for pure PAIR runs
  • Attack records include jailbreak_prompt and jailbreak_response fields (truncated at 500 chars in JSON export)

Caveats

  • Results are sensitive to attacker/judge model choice — the benchmark uses a fixed judge to ensure comparability.
  • PAIR can have high apparent MIR if the judge model is lenient; use consistent judge across all reported comparisons.