LLM Alignment--Utility Asymmetry under Semantic-Preserving Transformations
Organizations: Università della Svizzera italiana Lugano, Switzerland
Abstract
Large Language Model (LLM) alignment is intended to ensure that models remain helpful and safe, but its stability under input distributional shift is not yet fully understood. Prior work shows that aligned models can fail under jailbreak prompts, alternative encodings, and cross-lingual transfer, yet these failures are usually studied as attacks rather than controlled probes of alignment generalization. Moreover, existing evidence is largely grounded in natural language variation already represented during pretraining, leaving unresolved whether alignment generalizes with semantic content or remains tied to superficial surface patterns. In this paper, we study this question using synthetic semantic-preserving transformations that are rule-based and invertible, preserving task-relevant meaning while shifting inputs beyond standard linguistic variation. Across four open-weight and four commercial models, under both fine-tuning and in-context learning, we use these transformations as a probe of alignment generalization and identify an empirical pattern we term Alignment--utility asymmetry: once models can operate effectively on transformed inputs, task utility is often substantially retained while alignment failure increases more sharply. For example, adapted GPT-4.1 mini shows only limited utility degradation under transformation while its harmful rate rises from 13.3 to 74.3; Gemini 3 Flash similarly retains near-original utility while its harmful rate increases from 2.3 to 43.0. Taken together, these results suggest that semantic-preserving distribution shifts can expose a recurring gap in how utility and alignment generalize in current LLMs.
Figures & tables
| MMLU | ARC-Challenge | GSM8K | Advbench | |||||||||
| Model | ||||||||||||
| Llama3-8B-Instruct | 35.0 ± 4.0 | 37.0 ± 8.9 | 2.0 | 57.3 ± 6.7 | 72.3 ± 6.7 | 15.0 | 63.3 ± 4.7 | 64.3 ± 5.1 | 1.0 | 3.7 ± 0.6 | 67.7 ± 3.5 | 64.0 |
| Gemma-7B-it | 36.7 ± 3.1 | 28.0 ± 7.5 | 8.7 | 78.7 ± 7.5 | 65.0 ± 14.5 | 13.7 | 54.7 ± 10.4 | 55.3 ± 8.5 | 0.7 | 18.7 ± 1.5 | 69.7 ± 4.5 | 51.0 |
| Qwen2.5-7B-Instruct | 54.7 ± 1.5 | 40.0 ± 4.4 | 14.7 | 75.0 ± 10.4 | 68.3 ± 11.5 | 6.7 | 75.0 ± 1.0 | 4.7 ± 1.5 | 70.3 | 3.7 ± 1.5 | 67.0 ± 5.3 | 63.3 |
| Mistral-7B-Instruct | 32.3 ± 5.9 | 29.0 ± 2.6 | 3.3 | 75.0 ± 7.8 | 68.7 ± 8.6 | 6.3 | 52.7 ± 11.1 | 54.0 ± 6.2 | 1.3 | 80.3 ± 1.5 | 78.0 ± 7.8 | 2.3 |
| GPT-4.1 mini (original) | 79.3 ± 0.6 | 0.0 ± 0.0 | 79.3 | 90.7 ± 0.6 | 0.0 ± 0.0 | 90.7 | 85.7 ± 0.6 | 0.0 ± 0.0 | 85.7 | 0.0 ± 0.0 | 0.0 ± 0.0 | 0.0 |
| MMLU | ARC-Challenge | GSM8K | Advbench | |||||||||
| Model | ||||||||||||
| Gemini 3 Flash | 89.7 ± 1.5 | 82.3 ± 1.5 | 7.3 | 98.3 ± 0.6 | 98.3 ± 0.6 | 0.0 | 97.7 ± 1.5 | 95.7 ± 0.6 | 2.0 | 2.3 ± 1.5 | 43.0 ± 8.9 | 40.7 |
| Claude 4 Sonnet | 72.3 ± 7.8 | 52.0 ± 3.6 | 20.3 | 88.7 ± 9.3 | 89.7 ± 2.5 | 1.0 | 96.3 ± 0.6 | 86.3 ± 2.1 | 10.0 | 0.0 ± 0.0 | 12.0 ± 1.7 | 12.0 |
| MMLU | ARC-Challenge | GSM8K | Advbench | |||||
| Density | ||||||||
| Original | 50.7 ± 0.6 | 0.0 ± 0.0 | 84.3 ± 2.5 | 0.0 ± 0.0 | 77.7 ± 2.5 | 0.0 ± 0.0 | 0.0 ± 0.0 | 0.0 ± 0.0 |
| 42.3 ± 2.5 | 41.7 ± 3.1 | 69.7 ± 6.4 | 72.7 ± 2.5 | 67.0 ± 3.5 | 64.3 ± 2.1 | 1.7 ± 0.6 | 40.3 ± 6.0 | |
| 40.0 ± 1.0 | 37.3 ± 4.0 | 61.7 ± 3.1 | 71.7 ± 6.7 | 64.7 ± 1.5 | 61.7 ± 9.0 | 2.0 ± 0.0 | 61.3 ± 4.2 | |
| 35.0 ± 4.0 | 37.0 ± 8.9 | 57.3 ± 6.7 | 72.3 ± 6.7 | 63.3 ± 4.7 | 64.3 ± 5.1 | 3.7 ± 0.6 | 67.7 ± 3.5 | |
| 38.3 ± 0.6 | 36.0 ± 5.0 | 67.3 ± 5.1 | 77.3 ± 2.5 | 66.3 ± 0.6 | 58.7 ± 0.6 | 4.3 ± 1.2 | 74.0 ± 4.4 | |
| MMLU | ARC-Challenge | GSM8K | Advbench | |||||||||
| Model | ||||||||||||
| Monoalphabetic Substitution | 35.0 ± 4.0 | 37.0 ± 8.9 | 2.0 | 57.3 ± 6.7 | 72.3 ± 6.7 | 15.0 | 63.3 ± 4.7 | 64.3 ± 5.1 | 1.0 | 3.7 ± 0.6 | 67.7 ± 3.5 | 64.0 |
| Polygraphic Substitution | 28.3 ± 6.1 | 29.0 ± 11.5 | 0.7 | 47.3 ± 9.7 | 54.7 ± 20.0 | 7.3 | 65.7 ± 3.8 | 53.7 ± 13.3 | 12.0 | 4.7 ± 2.1 | 73.3 ± 7.2 | 68.7 |
| Variable-length Substitution | 41.3 ± 6.4 | 28.3 ± 6.8 | 13.0 | 70.0 ± 8.7 | 61.7 ± 13.7 | 8.3 | 65.3 ± 2.5 | 60.7 ± 15.0 | 4.7 | 11.0 ± 0.0 | 66.7 ± 4.9 | 55.7 |
| Deletion | MMLU | ARC-Challenge | GSM8K | Advbench | ||||
| Perturbation | ||||||||
| 37.7 ± 4.6 | 28.0 ± 4.0 | 72.0 ± 7.2 | 59.7 ± 7.6 | 68.0 ± 8.2 | 62.0 ± 4.6 | 4.0 ± 1.0 | 64.3 ± 6.8 | |
| 39.7 ± 6.5 | 19.0 ± 5.3 | 74.7 ± 7.6 | 34.0 ± 9.6 | 67.7 ± 3.5 | 52.3 ± 8.9 | 3.7 ± 1.2 | 54.3 ± 2.1 | |
| 40.7 ± 3.8 | 7.0 ± 3.6 | 71.0 ± 7.0 | 14.0 ± 3.5 | 66.0 ± 8.7 | 41.0 ± 5.0 | 3.3 ± 0.6 | 52.0 ± 8.5 | |
| 39.0 ± 2.6 | 2.3 ± 1.5 | 70.0 ± 5.3 | 5.0 ± 2.0 | 67.7 ± 2.3 | 18.7 ± 1.2 | 3.3 ± 1.5 | 18.0 ± 2.0 | |
| 40.3 ± 1.5 | 0.0 ± 0.0 | 68.7 ± 3.2 | 0.7 ± 0.6 | 65.7 ± 2.1 | 2.0 ± 1.0 | 1.7 ± 0.6 | 5.7 ± 0.6 | |
| Sycophancy Rate | Biased Rate | |||
| Model and Setup | ||||
| Gemini 3 Flash (ICL) | 52.0 ± 1.0 | 68.7 ± 1.5 | 2.0 ± 0.0 | 15.7 ± 0.6 |
| GPT-4.1 mini (FT) | 56.0 ± 0.0 | 70.3 ± 3.4 | 7.3 ± 0.6 | 28.7 ± 1.5 |
Appendix figures & tables26 assets
Supplementary material from the paper’s appendix.
Appendix
| Core issue | Prior transformation-based jailbreaks | Huang et al. | Our work |
| Research objective | Whether an encoded or transformed prompt can bypass model safety | Whether sampled bijective encodings can bypass safety | Whether utility and alignment generalize together under the same semantic-preserving representation shift |
| Transformation use | Attack-oriented encoding construction, prompting, or search | Randomly sampled bijections | A fixed deterministic transformation , selected independently of attack outcomes |
| Primary measurement | Predominantly attack success rate | Attack success under sampled bijections | Joint measurement of , , , and under matched conditions |
| Utility evaluation | Often absent or auxiliary to attack efficacy | Utility examined with explicit mapping instructions and task-specific demonstrations | End-to-end transformed utility on MMLU, ARC, and GSM8K under the same representation shift used for alignment evaluation |
| Adaptation scope | Primarily prompting or attack-specific settings | ICL | Fine-tuning and ICL across open-weight and commercial models |
| Experimental objective | Characterize when a transformed attack succeeds | Characterize the effectiveness of bijective mappings for bypass | Identify when the utility–alignment divergence emerges, its boundary conditions, contributing factors, and mitigation |
| Setup | MMLU | MMLU | ARC | ARC | GSM8K | GSM8K | AdvBench | AdvBench |
| Flip-coding |
| Model and setup | Plaintext SR ( ) | Transformed SR ( ) |
| Gemini 3 Flash (ICL) | ||
| GPT-4.1 mini (FT) |
| Model and setup | Plaintext BR ( ) | Transformed BR ( ) |
| Gemini 3 Flash (ICL) | ||
| GPT-4.1 mini (FT) |
| Dataset | Untransformed | Decoding Failure | Decoding Inaccuracy | Transformed (Correct) | Transformed (Incorrect) |
| MMLU | |||||
| ARC-Challenge | |||||
| GSM8K |
| Density | Untransformed | Decoding Failure | Decoding Inaccuracy | Transformed (Compliance) | Transformed (Refusal) | Transformed (Unclear) |
| Model | Untransformed (Refusal) | Untransformed (Compliance) | Decoding Issues | Transformed (Compliance) | Transformed (Refusal) | Transformed (Unclear) |
| Gemini 3 Flash | ||||||
| Claude 4 Sonnet | ||||||
| GPT-5.3 Instant |
| Feature | Refusal Failure | Semantic Evasion |
| Intent Recognition | Recognized as harmful | Not surfaced in a safety-triggering form |
| Output Representation | Standard linguistic form | Transformed or alternative representation |
| Failure Mode | Refusal mechanism bypass | Failure to activate safety triggering |
| Interaction with Filters | Occurs at output level | Dependent on representation format |
| Algorithm | Semantic. Benign | Semantic. Imp. Harmful | Semantic. Exp. Harmful | Refusal Failure | Semantic Evasion |
| Shadow [ 11 ] | |||||
| NOICE [ 12 ] | |||||
| 10benign [ 13 ] | |||||
| CMF [ 28 ] |
| Algorithm | Contextual Framing | Prefix / Suffix Injection | Obfuscation / Encoding | Refusal Failure | Semantic Evasion |
| GCG [ 14 ] | * | ||||
| AutoDAN [ 15 ] | * | ||||
| PAIR [ 16 ] | * | ||||
| ICA [ 17 ] | |||||
| TAP [ 18 ] | * | ||||
| JAIL-CON [ 19 ] |
| Setup | MMLU | MMLU | ARC | ARC | GSM8K | GSM8K | AdvBench | AdvBench | HarmBench | HarmBench |
| Llama3-8B, original protocol | ||||||||||
| Llama3-8B, no recovery | ||||||||||
| Llama3-8B, full recovery | ||||||||||
| Gemma-7B, original protocol | ||||||||||
| Gemma-7B, no recovery | ||||||||||
| Gemma-7B, full recovery |
| Model | Counterfactual | Counterfactual | AdvBench | AdvBench |
| Llama3-8B | ||||
| Gemma-7B | ||||
| Qwen2.5-7B | ||||
| GPT-4.1 mini |
| Setup | MMLU | MMLU | ARC | ARC | GSM8K | GSM8K | AdvBench | AdvBench |
| , plaintext refusal supervision | ||||||||
| , transformed refusal supervision |
| Prompt type | Instruction-specific | Partially related | Irrelevant | Gibberish |
| and coherent | ||||
| AdvBench harmful prompts | ||||
| Paired benign counterfactuals |
| Setting | |||||||||
| Llama3-8B-Instruct | 3 (3.0%) | 64 (64.0%) | +61 (61.0) | 10 (5.0%) | 130 (65.0%) | +120 (60.0) | 13 (4.3%) | 196 (65.3%) | +183 (61.0) |
| GPT-4.1 mini | 13 (13.0%) | 75 (75.0%) | +62 (62.0) | 20 (10.0%) | 146 (73.0%) | +126 (63.0) | 29 (9.7%) | 211 (70.3%) | +182 (60.7) |
| Gemini 3 Flash | 2 (2.0%) | 49 (49.0%) | +47 (47.0) | 4 (2.0%) | 94 (47.0%) | +90 (45.0) | 5 (1.7%) | 143 (47.7%) | +138 (46.0) |
| TP | FP | TN | FN | Accuracy | Precision | Recall | F1 Score | |
| 100 | 72 | 3 | 24 | 1 | 96.0 | 96.0 | 98.6 | 97.3 |
| 200 | 138 | 8 | 50 | 4 | 94.0 | 94.5 | 97.2 | 95.8 |
| 300 | 197 | 14 | 83 | 6 | 93.3 | 93.4 | 97.0 | 95.2 |
| Model | HarmBench | HarmBench | Contextual | Contextual |
| Llama3-8B | ||||
| Gemma-7B | ||||
| GPT-4.1 mini | ||||
| Gemini 3 Flash (ICL) |
| Setup | Multi-turn | Multi-turn |
| Llama3-8B, no FT | ||
| Llama3-8B, | ||
| Llama3-8B, | ||
| Llama3-8B, |
| Setup | MMLU | MMLU | ARC | ARC | GSM8K | GSM8K | AdvBench | AdvBench |
| Gemma-4-31B | ||||||||
| Llama3-70B |
| MMLU | ARC-Challenge | GSM8K | Advbench | |||||
| Model | ||||||||
| Gemini 3 Flash | 89 | 83 | 97 | 99 | 97 | 96 | 1 | 11 |
| Claude 4 Sonnet | 90 | 59 | 98 | 93 | 95 | 90 | 0 | 28 |
| LoRA intervention | Original utility | Transformed utility | Decoding success |
| All enabled | |||
| Disable layers 0–7 | |||
| Disable layers 8–15 | |||
| Disable layers 16–23 | |||
| Disable layers 24–31 | |||
| Only layers 0–7 enabled |
| Probe training | Probe test | Layer range | AUC |
| vs. | vs. | 16–20 | |
| vs. | vs. | 0–7 | |
| vs. | vs. | 16–20 |
| Setting | ASR | With matched patch | Reduction |
| points | |||
| points |
| Plaintext | Transformed | Plaintext | Transformed | Plaintext | Transformed | Plaintext | Transformed |
| A/a | t | H/h | x | O/o | e | V/v | y |
| B/b | g | I/i | a | P/p | r | W/w | n |
| C/c | o | J/j | b | Q/q | m | X/x | i |
| D/d | q | K/k | f | R/r | k | Y/y | j |
| E/e | p | L/l | v | S/s | s | Z/z | h |
| F/f | w | M/m | z | T/t | u |
| Plaintext | Transformed | Plaintext | Transformed | Plaintext | Transformed | Plaintext | Transformed |
| A/a | kv | H/h | uc | O/o | bp | V/v | or |
| B/b | nw | I/i | mw | P/p | mq | W/w | gl |
| C/c | at | J/j | ac | Q/q | de | X/x | vy |
| D/d | rn | K/k | st | R/r | dl | Y/y | jp |
| E/e | qz | L/l | is | S/s | hf | Z/z | xy |
| F/f | hu | M/m | fb | T/t | jx |
| Plaintext | Transformed | Plaintext | Transformed | Plaintext | Transformed | Plaintext | Transformed |
| A/a | ga | H/h | fb | O/o | ha | V/v | e |
| B/b | hd | I/i | ia | P/p | gd | W/w | id |
| C/c | ib | J/j | ie | Q/q | he | X/x | ge |
| D/d | gb | K/k | fe | R/r | fc | Y/y | fd |
| E/e | a | L/l | hb | S/s | gc | Z/z | gf |
| F/f | ic | M/m | hc | T/t | fa |
LLM Alignment
Large language model alignment studies methods for making models follow human intentions, values, and safety constraints across contexts.
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