Pith. sign in

REVIEW 1 major objections 45 references

CLIP embeddings detect adversarial attacks in a zero-shot black-box manner by identifying non-arbitrary shifts from perturbations.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review · grok-4.3

2026-07-01 06:42 UTC pith:3APCNZZC

load-bearing objection CLIP is used here for zero-shot attack detection in a fully agnostic way, but the key claim rests on an unproven assumption about consistent embedding shifts. the 1 major comments →

arxiv 2606.30342 v2 pith:3APCNZZC submitted 2026-06-29 cs.CV

A Classifier-Agnostic Zero-Shot Adversarial Attack Detection via CLIP

classification cs.CV
keywords adversarial attack detectionzero-shot detectionCLIPblack-box detectionclassifier-agnosticimage classificationadversarial robustness
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper establishes a method called A^4D that uses prompt-based similarity scores from CLIP to detect adversarial attacks. It does so without any knowledge of the specific attack, the target classifier, or access to adversarial training samples. This matters because most existing detectors are limited by their dependence on particular attacks or models, limiting their practicality. A sympathetic reader would care if this provides a general way to safeguard deep learning systems against unseen threats across diverse scenarios.

Core claim

The central claim is that A^4D, a detector relying on CLIP's prompt similarities, achieves state-of-the-art performance in detecting adversarial attacks in fully attack-agnostic and classifier-agnostic settings, based on the observations that CLIP is sensitive to imperceptible perturbations and that the resulting embedding shifts are structured enough to serve as reliable indicators.

What carries the argument

Prompt-based similarity scores derived from CLIP, which quantify how well an input image matches various text prompts and thereby reveal perturbation effects.

Load-bearing premise

The shift in CLIP embedding space caused by adversarial perturbations is not arbitrary and can be used as a robust attack indicator.

What would settle it

Finding a set of adversarial attacks where the CLIP similarity scores fail to separate clean images from attacked ones with high accuracy would disprove the claim.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • Adversarial detection becomes possible without white-box access to the classifier.
  • The method requires no training on specific adversarial examples.
  • Performance holds across multiple attack types and datasets.
  • Detection works in a completely black-box zero-shot fashion.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Such an approach might extend to detecting other types of image manipulations beyond adversarial attacks.
  • Integrating CLIP-based detection could improve robustness in deployed vision systems without retraining models.
  • The non-arbitrary nature of shifts suggests potential for analyzing the direction of perturbations for attack characterization.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

1 major / 0 minor

Summary. The paper proposes A^4D, a black-box zero-shot adversarial attack detector that relies on prompt-based similarity scores from CLIP. It rests on two observations: CLIP's sensitivity to small non-semantic perturbations and the claim that embedding-space shifts under attack are non-arbitrary and thus usable as a robust indicator. The manuscript asserts that this yields SOTA detection performance in fully attack-agnostic and classifier-agnostic settings across multiple attacks, datasets, and models.

Significance. A working version of the method would be significant as the first reported use of CLIP for zero-shot adversarial detection without attack-specific assumptions or white-box access. It could offer a practical, general-purpose detector if the embedding-shift property holds invariantly.

major comments (1)
  1. [Abstract] Abstract, observation (ii): The assertion that 'the shift in CLIP embedding space is not arbitrary and can be used as a robust attack indicator' is presented without derivation, statistical test, invariance argument, or empirical quantification of consistency across attacks or images. This assumption is load-bearing for the attack-agnostic and classifier-agnostic SOTA claim; if the shift direction or magnitude varies with attack type or image content, the reported detection results cannot be attributed to a general CLIP property.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the constructive feedback on our manuscript. We address the major comment point by point below.

read point-by-point responses
  1. Referee: [Abstract] Abstract, observation (ii): The assertion that 'the shift in CLIP embedding space is not arbitrary and can be used as a robust attack indicator' is presented without derivation, statistical test, invariance argument, or empirical quantification of consistency across attacks or images. This assumption is load-bearing for the attack-agnostic and classifier-agnostic SOTA claim; if the shift direction or magnitude varies with attack type or image content, the reported detection results cannot be attributed to a general CLIP property.

    Authors: We agree that the abstract presents observation (ii) concisely without supporting details. The manuscript's experimental section demonstrates the claim empirically by showing that A^4D achieves strong detection performance consistently across multiple attacks, datasets, and classifiers in fully agnostic settings; this performance would not hold if shifts were arbitrary. To directly address the concern, the revised manuscript will add a dedicated analysis subsection providing statistical quantification of shift consistency (e.g., variance in direction and magnitude across attacks and images) and a brief invariance argument grounded in CLIP's contrastive training objective. revision: yes

Circularity Check

0 steps flagged

No circularity detected; empirical observations and experimental validation are independent of inputs

full rationale

The paper states its method rests on two explicit observations about CLIP behavior and validates performance via experiments across multiple attacks, datasets, and classifiers. No equations, fitted parameters renamed as predictions, self-citations, or uniqueness theorems are present in the provided text that would reduce the central claim to a definitional or fitted input by construction. The approach is therefore self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Abstract-only review; no explicit free parameters, axioms, or invented entities are stated. The two observations function as domain assumptions but are not formalized.

pith-pipeline@v0.9.1-grok · 5703 in / 985 out tokens · 22793 ms · 2026-07-01T06:42:33.144480+00:00 · methodology

0 comments
read the original abstract

Adversarial attacks pose a challenge to the reliability of deep learning models, motivating effective detection methods. Existing techniques often rely on attack-specific assumptions, access to adversarial samples, or knowledge of the underlying classifier (white-box). We propose $A^4D$ Attack- and Architecture-Agnostic Adversarial Detector, a completely black-box, zero-shot adversarial attack detection framework that utilizes prompt-based similarity scores derived from CLIP. To the best of our knowledge this is the first attempt to utilize CLIP for such a task. The method is based on two key observations: (i) CLIP is sensitive even to small imperceptible non-semantic perturbations; (ii) The shift in CLIP embedding space is not arbitrary and can be used as a robust attack indicator. Experiments across multiple attacks, datasets and classifiers validate that $A^4D$ achieves SOTA detection results in the attack-agnostic and classifier-agnostic setting.

Figures

Figures reproduced from arXiv: 2606.30342 by Eyal Gofer, Guy Gilboa, Hodaya Krakover, Meir Yossef Levi.

Figure 1
Figure 1. Figure 1: CLIP sensitivity to adversarial perturbations. [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Test-time zero-shot adversarial detection pipeline [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Qualitative examples of clean and adversarial images under different [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Prompt-specific detection behavior. Three examples illustrating the sim￾ilarity between images and three specific text prompts are shown. Only the first two prompts are included in the final prompt dictionary. For the first two prompts, a clear separation between clean and adversarial samples is observed for most attack types, with DeepFool and CW being the most challenging to distinguish. The behavior var… view at source ↗
Figure 5
Figure 5. Figure 5: Pairwise correlation heatmap of the prompt-based similarity scores computed using CLIP. Prompts are indexed according to [PITH_FULL_IMAGE:figures/full_fig_p009_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Qualitative examples of clean and adversarial images under the same [PITH_FULL_IMAGE:figures/full_fig_p010_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: Relationship between perturbation characteristics and detection per [PITH_FULL_IMAGE:figures/full_fig_p012_7.png] view at source ↗
Figure 5
Figure 5. Figure 5: However, a more systematic procedure for prompt selection could be de [PITH_FULL_IMAGE:figures/full_fig_p013_5.png] view at source ↗

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

45 extracted references · 13 canonical work pages · 8 internal anchors

  1. [1]

    In: European conference on computer vision

    Andriushchenko, M., Croce, F., Flammarion, N., Hein, M.: Square attack: a query- efficient black-box adversarial attack via random search. In: European conference on computer vision. pp. 484–501. Springer (2020)

  2. [2]

    In: 42nd International conference on machine learning (2025)

    Betser, R., Levi, M.Y., Gilboa, G.: Whitened clip as a likelihood surrogate of images and captions. In: 42nd International conference on machine learning (2025)

  3. [3]

    In: Euro- pean Conference on Computer Vision

    Cao, Y., Zhang, J., Frittoli, L., Cheng, Y., Shen, W., Boracchi, G.: Adaclip: Adapt- ing clip with hybrid learnable prompts for zero-shot anomaly detection. In: Euro- pean Conference on Computer Vision. pp. 55–72. Springer (2024) A Classifier-Agnostic Zero-Shot Adversarial Attack Detection via CLIP 15

  4. [4]

    In: 2017 ieee symposium on security and privacy (sp)

    Carlini, N., Wagner, D.: Towards evaluating the robustness of neural networks. In: 2017 ieee symposium on security and privacy (sp). pp. 39–57. Ieee (2017)

  5. [5]

    In: international conference on machine learning

    Cohen, J., Rosenfeld, E., Kolter, Z.: Certified adversarial robustness via random- ized smoothing. In: international conference on machine learning. pp. 1310–1320. PMLR (2019)

  6. [6]

    In: International conference on machine learning

    Croce, F., Hein, M.: Reliable evaluation of adversarial robustness with an ensemble of diverse parameter-free attacks. In: International conference on machine learning. pp. 2206–2216. PMLR (2020)

  7. [7]

    In: European conference on computer vision

    Crowson, K., Biderman, S., Kornis, D., Stander, D., Hallahan, E., Castricato, L., Raff, E.: Vqgan-clip: Open domain image generation and editing with natural lan- guage guidance. In: European conference on computer vision. pp. 88–105. Springer (2022)

  8. [8]

    Electronics 14(15), 3015 (2025)

    Danesh, W., Sapireddy, S.R., Rahman, M.: Understanding and detecting adversar- ial examples in iot networks: A white-box analysis with autoencoders. Electronics 14(15), 3015 (2025)

  9. [9]

    Detecting Adversarial Samples from Artifacts

    Feinman, R., Curtin, R.R., Shintre, S., Gardner, A.B.: Detecting adversarial sam- ples from artifacts. arXiv preprint arXiv:1703.00410 (2017)

  10. [10]

    Explaining and Harnessing Adversarial Examples

    Goodfellow, I.J., Shlens, J., Szegedy, C.: Explaining and harnessing adversarial examples. arXiv preprint arXiv:1412.6572 (2014)

  11. [11]

    He,K.,Zhang,X.,Ren,S.,Sun,J.:Deepresiduallearningforimagerecognition.In: Proceedings of the IEEE conference on computer vision and pattern recognition. pp. 770–778 (2016)

  12. [12]

    In: Proceedings of the IEEE/CVF conference on computer vision and pattern recognition

    Hendrycks, D., Zhao, K., Basart, S., Steinhardt, J., Song, D.: Natural adversarial examples. In: Proceedings of the IEEE/CVF conference on computer vision and pattern recognition. pp. 15262–15271 (2021)

  13. [13]

    Scientific Data12(1), 92 (2025).https://doi.org/10.1038/s41597-024-04295- 9,https://doi.org/10.1038/s41597-024-04295-9

    Kapp, A., Hoffmann, E., Weigmann, E., Mihaljević, H.: StreetSurfaceVis: a dataset of crowdsourced street-level imagery annotated by road surface type and quality. Scientific Data12(1), 92 (2025).https://doi.org/10.1038/s41597-024-04295- 9,https://doi.org/10.1038/s41597-024-04295-9

  14. [14]

    Torchattacks: A pytorch repository for adversar- ial attacks.arXiv preprint arXiv:2010.01950, 2020

    Kim, H.: Torchattacks: A pytorch repository for adversarial attacks. arXiv preprint arXiv:2010.01950 (2020)

  15. [15]

    In: Artificial intelligence safety and security, pp

    Kurakin, A., Goodfellow, I.J., Bengio, S.: Adversarial examples in the physical world. In: Artificial intelligence safety and security, pp. 99–112. Chapman and Hall/CRC (2018)

  16. [16]

    Advances in neural information processing systems31(2018)

    Lee, K., Lee, K., Lee, H., Shin, J.: A simple unified framework for detecting out- of-distribution samples and adversarial attacks. Advances in neural information processing systems31(2018)

  17. [17]

    In: Proceedings of the 42nd International Conference on Machine Learning

    Levi, M.Y., Gilboa, G.: The double ellipsoid geometry of clip. In: Proceedings of the 42nd International Conference on Machine Learning. Proceedings of Machine Learning Research, vol. 267. PMLR, Vancouver, Canada (2025)

  18. [18]

    IEEE Transactions on Information Forensics and Security (2025)

    Li, Q., Wu, C., Chen, J., Zhang, Z., He, K., Du, R., Wang, X., Zhao, Q., Liu, Y.: Privacy-preserving universal adversarial defense for black-box models. IEEE Transactions on Information Forensics and Security (2025)

  19. [19]

    Electronics11(8), 1283 (2022)

    Liang, H., He, E., Zhao, Y., Jia, Z., Li, H.: Adversarial attack and defense: A survey. Electronics11(8), 1283 (2022)

  20. [20]

    In: Proceedings of the IEEE/CVF conference on computer vision and pattern recognition

    Liu, Z., Mao, H., Wu, C.Y., Feichtenhofer, C., Darrell, T., Xie, S.: A convnet for the 2020s. In: Proceedings of the IEEE/CVF conference on computer vision and pattern recognition. pp. 11976–11986 (2022)

  21. [21]

    Neuro- computing508, 293–304 (2022) 16 H

    Luo, H., Ji, L., Zhong, M., Chen, Y., Lei, W., Duan, N., Li, T.: Clip4clip: An empirical study of clip for end to end video clip retrieval and captioning. Neuro- computing508, 293–304 (2022) 16 H. Krakover et al

  22. [22]

    In: Pro- ceedings of the Computer Vision and Pattern Recognition Conference

    Ma,W.,Zhang,X.,Yao,Q.,Tang,F.,Wu,C.,Li,Y.,Yan,R.,Jiang,Z.,Zhou,S.K.: Aa-clip: Enhancing zero-shot anomaly detection via anomaly-aware clip. In: Pro- ceedings of the Computer Vision and Pattern Recognition Conference. pp. 4744– 4754 (2025)

  23. [23]

    Characterizing Adversarial Subspaces Using Local Intrinsic Dimensionality

    Ma, X., Li, B., Wang, Y., Erfani, S.M., Wijewickrema, S., Schoenebeck, G., Song, D., Houle, M.E., Bailey, J.: Characterizing adversarial subspaces using local intrin- sic dimensionality. arXiv preprint arXiv:1801.02613 (2018)

  24. [24]

    Towards Deep Learning Models Resistant to Adversarial Attacks

    Madry, A., Makelov, A., Schmidt, L., Tsipras, D., Vladu, A.: Towards deep learning models resistant to adversarial attacks. arXiv preprint arXiv:1706.06083 (2017)

  25. [25]

    In: Proceedings of the 2017 ACM SIGSAC conference on computer and communi- cations security

    Meng, D., Chen, H.: Magnet: a two-pronged defense against adversarial examples. In: Proceedings of the 2017 ACM SIGSAC conference on computer and communi- cations security. pp. 135–147 (2017)

  26. [26]

    On Detecting Adversarial Perturbations

    Metzen, J.H., Genewein, T., Fischer, V., Bischoff, B.: On detecting adversarial perturbations. arXiv preprint arXiv:1702.04267 (2017)

  27. [27]

    mnmoustafa, Ali, M.: Tiny imagenet.https://kaggle.com/competitions/tiny- imagenet(2017), kaggle

  28. [28]

    In: Proceedings of the IEEE conference on computer vision and pattern recognition

    Moosavi-Dezfooli, S.M., Fawzi, A., Frossard, P.: Deepfool: a simple and accurate method to fool deep neural networks. In: Proceedings of the IEEE conference on computer vision and pattern recognition. pp. 2574–2582 (2016)

  29. [29]

    arXiv preprint arXiv:2508.21715 (2025)

    Nazeri, A., Hafez, W.: Entropy-based non-invasive reliability monitoring of convo- lutional neural networks. arXiv preprint arXiv:2508.21715 (2025)

  30. [30]

    Deep k-Nearest Neighbors: Towards Confident, Interpretable and Robust Deep Learning

    Papernot, N., McDaniel, P.: Deep k-nearest neighbors: Towards confident, inter- pretable and robust deep learning. arXiv preprint arXiv:1803.04765 (2018)

  31. [31]

    In: Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition

    Peng, Z., Xu, Z., Zeng, Z., Wen, C., Huang, Y., Yang, M., Tang, F., Shen, W.: Understanding fine-tuning clip for open-vocabulary semantic segmentation in hy- perbolic space. In: Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition. pp. 4562–4572 (2025)

  32. [32]

    In: International conference on machine learning

    Radford, A., Kim, J.W., Hallacy, C., Ramesh, A., Goh, G., Agarwal, S., Sastry, G., Askell, A., Mishkin, P., Clark, J., et al.: Learning transferable visual models from natural language supervision. In: International conference on machine learning. pp. 8748–8763. PmLR (2021)

  33. [33]

    In: International conference on machine learning

    Ramesh, A., Pavlov, M., Goh, G., Gray, S., Voss, C., Radford, A., Chen, M., Sutskever, I.: Zero-shot text-to-image generation. In: International conference on machine learning. pp. 8821–8831. Pmlr (2021)

  34. [34]

    Advances in neural information processing systems35, 36479–36494 (2022)

    Saharia, C., Chan, W., Saxena, S., Li, L., Whang, J., Denton, E.L., Ghasemipour, K., Gontijo Lopes, R., Karagol Ayan, B., Salimans, T., et al.: Photorealistic text- to-image diffusion models with deep language understanding. Advances in neural information processing systems35, 36479–36494 (2022)

  35. [35]

    Shafahi, A., Najibi, M., Ghiasi, M.A., Xu, Z., Dickerson, J., Studer, C., Davis, L.S., Taylor, G., Goldstein, T.: Adversarial training for free! Advances in neural information processing systems32(2019)

  36. [36]

    Frontiers in Computer Science7, 1631561 (2025)

    Stenhuis, R., Liu, D., Qiao, Y., Conti, M., Panaousis, M., Liang, K.: Meetsafe: en- hancing robustness against white-box adversarial examples. Frontiers in Computer Science7, 1631561 (2025)

  37. [37]

    In: 2023 IEEE Applied Imagery Pattern Recognition Workshop (AIPR)

    Sultan, M., Jacobs, L., Stylianou, A., Pless, R.: Exploring clip for real world, text-based image retrieval. In: 2023 IEEE Applied Imagery Pattern Recognition Workshop (AIPR). pp. 1–6. IEEE (2023)

  38. [38]

    In: International conference on machine learning

    Touvron, H., Cord, M., Douze, M., Massa, F., Sablayrolles, A., Jégou, H.: Training data-efficient image transformers & distillation through attention. In: International conference on machine learning. pp. 10347–10357. PMLR (2021) A Classifier-Agnostic Zero-Shot Adversarial Attack Detection via CLIP 17

  39. [39]

    In: Proceedings of the IEEE/CVF conference on computer vision and pattern recognition

    Wei, Y., Cao, Y., Zhang, Z., Peng, H., Yao, Z., Xie, Z., Hu, H., Guo, B.: iclip: Bridgingimageclassificationandcontrastivelanguage-imagepre-trainingforvisual recognition. In: Proceedings of the IEEE/CVF conference on computer vision and pattern recognition. pp. 2776–2786 (2023)

  40. [40]

    In: Interna- tional conference on machine learning

    Weng, Z., Yang, X., Li, A., Wu, Z., Jiang, Y.G.: Open-vclip: Transforming clip to an open-vocabulary video model via interpolated weight optimization. In: Interna- tional conference on machine learning. pp. 36978–36989. PMLR (2023)

  41. [41]

    arXiv preprint arXiv:2310.01403 (2023)

    Wu, S., Zhang, W., Xu, L., Jin, S., Li, X., Liu, W., Loy, C.C.: Clipself: Vision transformer distills itself for open-vocabulary dense prediction. arXiv preprint arXiv:2310.01403 (2023)

  42. [42]

    Feature Squeezing: Detecting Adversarial Examples in Deep Neural Networks

    Xu, W., Evans, D., Qi, Y.: Feature squeezing: Detecting adversarial examples in deep neural networks. arXiv preprint arXiv:1704.01155 (2017)

  43. [43]

    Wide Residual Networks

    Zagoruyko, S., Komodakis, N.: Wide residual networks. arXiv preprint arXiv:1605.07146 (2016)

  44. [44]

    In: The 22nd International Conference on Artificial Intelligence and Statistics

    Zhang, Y., Liang, P.: Defending against whitebox adversarial attacks via random- ized discretization. In: The 22nd International Conference on Artificial Intelligence and Statistics. pp. 684–693. PMLR (2019)

  45. [45]

    arXiv preprint arXiv:2310.18961 , year=

    Zhou, Q., Pang, G., Tian, Y., He, S., Chen, J.: Anomalyclip: Object-agnostic prompt learning for zero-shot anomaly detection. arXiv preprint arXiv:2310.18961 (2023)