Adversarial-example-based fingerprinting approaches, which leverage the decision boundary characteristics of deep neural networks (DNNs) to craft fingerprints, have proven effective for model ownership protection. However, a fundamental challenge remains unresolved: how far a fingerprint should be placed from the decision boundary to simultaneously satisfy two essential properties, i.e., robustness and uniqueness, for effective and reliable ownership protection. Despite the importance of the fingerprint-to-boundary distance, existing works lack a theoretical solution and instead rely on empirical heuristics, which may violate either robustness or uniqueness properties. We propose AnaFP, an analytical fingerprinting scheme that constructs fingerprints under theoretical guidance. Specifically, we formulate fingerprint generation as controlling the fingerprint-to-boundary distance through a tunable stretch factor. To ensure both robustness and uniqueness, we mathematically formalize these properties that determine the lower and upper bounds of the stretch factor. These bounds jointly define an admissible interval within which the stretch factor must lie, thereby establishing a theoretical connection between the two constraints and the fingerprint-to-boundary distance. To enable practical fingerprint generation, we approximate the original (infinite) sets of pirated and independently trained models using two finite surrogate model pools and employ a quantile-based relaxation strategy to relax the derived bounds. Due to the circular dependency between the lower bound and the stretch factor, we apply grid search over the admissible interval to determine the most feasible stretch factor. Extensive experimental results show that AnaFP consistently outperforms prior methods, achieving effective ownership verification across diverse model architectures and model modification attacks.
Figures & tables
Figure 1: A typical model fingerprinting scenario.
Figure 2: The pipeline of fingerprint generation and ownership verification.
Method
CNN (CIFAR-10)
CNN (CIFAR-100)
MLP (MNIST)
GNN (PROTEINS)
AnaFP (ours)
0.957 ± 0.002
0.893 ± 0.005
0.963 ± 0.002
0.926 ± 0.005
UAP
0.850 ± 0.010
0.806 ± 0.021
0.906 ± 0.004
–
IPGuard
0.715 ± 0.075
0.725 ± 0.090
0.873 ± 0.018
0.636 ± 0.067
MarginFinger
0.671 ± 0.064
0.630 ± 0.072
0.653 ± 0.051
–
AKH
0.723 ± 0.016
0.802 ± 0.019
0.851 ± 0.013
0.854 ± 0.021
ADV-TRA
0.878 ± 0.012
0.850 ± 0.024
0.887 ± 0.005
–
Table 1: AUCs achieved by different approaches across DNN models and datasets.
Figure 3: (a) The ROC curve and (b) the matching rate distribution.
Method
Pruning
Fine-tuning
KD
AT
N-finetune
P-finetune
Prune-KD
AnaFP (ours)
1.000 ± 0.000
0.979 ± 0.008
0.756 ± 0.023
0.983 ± 0.015
0.978 ± 0.010
0.989 ± 0.007
0.689 ± 0.031
UAP
1.000 ± 0.000
0.868 ± 0.023
0.679 ± 0.013
0.783 ± 0.041
0.870 ± 0.021
0.876 ± 0.022
0.625 ± 0.026
IPGuard
0.999 ± 0.002
0.741 ± 0.113
0.559 ± 0.105
0.616 ± 0.026
0.679 ± 0.104
0.671 ± 0.106
0.596 ± 0.079
MarginFinger
1.000 ± 0.000
0.658 ± 0.119
0.554 ± 0.083
0.672 ± 0.087
0.586 ± 0.064
0.638 ± 0.115
0.543 ± 0.088
AKH
0.999 ± 0.001
0.848 ± 0.016
0.616 ± 0.054
0.627 ± 0.122
0.716 ± 0.039
0.701 ± 0.052
0.636 ± 0.047
ADV-TRA
1.000 ± 0.000
0.923 ± 0.010
0.660 ± 0.025
0.742 ± 0.036
0.895 ± 0.032
0.857 ± 0.013
0.633 ± 0.035
Table 2: AUCs under various performance-preserving model modifications.
Figure 4: Line plot (top axis): effect of surrogate pool size; Bar plot (bottom axis): effect of surrogate pool diversity.
qmargin/qlip
0.1/0.9
0.2/0.8
0.3/0.7
0.4/0.6
0.5/0.5
0.6/0.4
0.7/0.3
0.8/0.2
0.9/0.1
Valid Fingerprints
0
0
11
33
56
103
228
428
1158
AUC
–
–
0.848
0.906
0.957
0.959
0.951
0.938
0.896
Table 3: Effect of the quantile thresholds.
Figure 5: The AUCs achieved by AnaFP and three variants.
Appendix figures & tables7 assets
Supplementary material from the paper’s appendix.
Appendix
Method
Pruning
Finetuning
KD
AT
N-finetune
P-finetune
Prune-KD
AnaFP (ours)
0.963 ± 0.002
0.954 ± 0.004
0.596 ± 0.009
0.930 ± 0.007
0.957 ± 0.005
0.956 ± 0.004
0.574 ± 0.013
UAP
0.897 ± 0.015
0.852 ± 0.022
0.598 ± 0.018
0.802 ± 0.027
0.852 ± 0.022
0.859 ± 0.021
0.583 ± 0.019
IPGuard
0.845 ± 0.086
0.811 ± 0.092
0.461 ± 0.096
0.721 ± 0.080
0.763 ± 0.088
0.750 ± 0.098
0.496 ± 0.078
MarginFinger
0.737 ± 0.076
0.667 ± 0.092
0.519 ± 0.026
0.679 ± 0.092
0.653 ± 0.089
0.553 ± 0.058
0.488 ± 0.026
AKH
0.915 ± 0.007
0.838 ± 0.032
0.592 ± 0.034
0.762 ± 0.076
0.829 ± 0.040
0.878 ± 0.044
0.601 ± 0.041
ADV-TRA
0.953 ± 0.007
0.904 ± 0.024
0.561 ± 0.011
0.886 ± 0.035
0.901 ± 0.017
0.898 ± 0.031
0.544 ± 0.030
Appendix
Table 4: AUCs under various performance-preserving model modifications on CNN models trained on CIFAR100.
Method
Pruning
Finetuning
KD
AT
N-finetune
P-finetune
Prune-KD
AnaFP (ours)
1.000 ± 0.000
1.000 ± 0.000
0.792 ± 0.002
0.987 ± 0.005
1.000 ± 0.000
0.999 ± 0.000
0.788 ± 0.006
UAP
0.981 ± 0.001
0.969 ± 0.006
0.635 ± 0.002
0.931 ± 0.010
0.968 ± 0.007
0.976 ± 0.003
0.610 ± 0.005
IPGuard
0.924 ± 0.042
0.983 ± 0.007
0.535 ± 0.036
0.902 ± 0.029
0.938 ± 0.008
0.922 ± 0.037
0.517 ± 0.029
MarginFinger
0.708 ± 0.130
0.750 ± 0.145
0.572 ± 0.041
0.762 ± 0.149
0.759 ± 0.146
0.586 ± 0.090
0.570 ± 0.034
AKH
0.849 ± 0.017
0.870 ± 0.023
0.765 ± 0.008
0.897 ± 0.026
0.864 ± 0.025
0.777 ± 0.009
0.759 ± 0.011
ADV-TRA
0.971 ± 0.010
0.964 ± 0.007
0.596 ± 0.011
0.907 ± 0.005
0.922 ± 0.004
0.953 ± 0.001
0.602 ± 0.005
Appendix
Table 5: AUCs under various performance-preserving model modifications on MLP models.
Method
Pruning
Finetuning
KD
AT
N-finetune
P-finetune
Prune-KD
AnaFP (ours)
0.933 ± 0.002
0.971 ± 0.007
0.806 ± 0.002
0.970 ± 0.012
0.962 ± 0.013
0.913 ± 0.006
0.736 ± 0.015
IPGuard
0.806 ± 0.051
0.668 ± 0.053
0.529 ± 0.330
0.612 ± 0.122
0669 ± 0.027
0.551 ± 0.074
0.571 ± 0.174
AKH
0.859 ± 0.011
0.831 ± 0.043
0.790 ± 0.021
0.869 ± 0.045
0.838 ± 0.041
0.849 ± 0.038
0.719 ± 0.036
Appendix
Table 6: AUCs under various performance-preserving model modifications on GNN models.
Method
TPR
FPR
TNR
FNR
AnaFP (ours)
0.80
0.22
0.78
0.20
UAP
0.73
0.30
0.70
0.27
IPGuard
0.58
0.46
0.54
0.42
MarginFinger
0.57
0.47
0.53
0.43
AKH
0.63
0.40
0.60
0.37
ADV-TRA
0.75
0.27
0.73
0.25
Appendix
Table 7: Detection performance under the KD attack for CNN/CIFAR10.
ResNet-18
ViT-S/16
Time
Memory
Time
Memory
AnaFP (ours)
33 m 8 s
13 GB
1 h 26 m
40 GB
UAP
4 h 55 m
4 GB
8 h 10 m
10 GB
IPGuard
1 m 6 s
1 GB
1 m 41 s
3 GB
MarginFinger
51 m 18 s
4 GB
1 h 14 m
10 GB
AKH
20 s
1 GB
1 m 10 s
3 GB
Appendix
Table 8: Time cost and peak GPU memory consumption of different fingerprinting methods under two representative protected models.
Protected Model
Surrogate pool size
Step 1
Step 2
Step 3
ViT-S/16
4
63s
3856s
1276s
ResNet18
4
8s
1004s
976s
ViT-S/16
8
61s
3855s
2121s
ResNet18
8
8s
997s
1419s
Appendix
Table 9: Time cost for the three fingerprint-generation steps: Step 1 (anchor selection), Step 2 (adversarial perturbation generation), and Step 3 ( τ search).
Protected Model
Surrogates
Step 2
Step 3
ViT-S/16
4
40G
3G
ResNet18
4
13G
1G
ViT-S/16
8
41G
3.2G
ResNet18
8
13G
1.1G
Appendix
Table 10: Peak memory consumption for Step 2 (adversarial perturbation generation) and Step 3 (grid search).