Papers › Improved techniques for deterministic l2 robustness

Improved techniques for deterministic l2 robustness

15 Nov 2022arXiv:2211.08453archive 2025-07-28

Sahil Singla, Soheil Feizi

Training convolutional neural networks (CNNs) with a strict 1-Lipschitz constraint under the l₂ norm is useful for adversarial robustness, interpretable gradients and stable training. 1-Lipschitz CNNs are usually designed by enforcing each layer to have an orthogonal Jacobian matrix (for all inputs) to prevent the gradients from vanishing during backpropagation. However, their performance often significantly lags behind that of heuristic methods to enforce Lipschitz constraints where the resulting CNN is not \textit{provably} 1-Lipschitz. In this work, we reduce this gap by introducing (a) a procedure to certify robustness of 1-Lipschitz CNNs by replacing the last linear layer with a 1-hidden layer MLP that significantly improves their performance for both standard and provably robust accuracy, (b) a method to significantly reduce the training time per epoch for Skew Orthogonal Convolution (SOC) layers (>30\% reduction for deeper networks) and (c) a class of pooling layers using the mathematical property that the l₂ distance of an input to a manifold is 1-Lipschitz. Using these methods, we significantly advance the state-of-the-art for standard and provable robust accuracies on CIFAR-10 (gains of +1.79\% and +3.82\%) and similarly on CIFAR-100 (+3.78\% and +4.75\%) across all networks. Code is available at \url{https://github.com/singlasahil14/improved_l2_robustness}.

PaperPDFCodeCode Syntology ran

In Syntology Open this paper in Syntology's Atlas, the map of the papers in Syntology's graph and their citations.

For agents, Syntology's MCP tool lists every function and class Syntology harvested from this paper and whether it ran (how to connect): get_harvested_code_for_paper(arxiv_id="2211.08453")

Code

Syntology Ran 6 of 7 code samples harvested from 1 repository linked to this paper; 1 has no recorded run. Of those that ran: 1 ran · our draft was wrong; 3 ran · fixture could not drive it; 2 ran with no contract checked.

By repository: official repository: 7 samples from 1 repository, 6 ran. The run record, sample by sample. “Ran” means executed on a synthesized input, not that the code is correct or reproduces the paper.

singlasahil14/improved_l2_robustness officialmentioned in paperpytorch report

Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.

Code Syntology ran Syntology

7 samples harvested; 6 ran; 0 honoured the contract we drafted; 1 has no recorded run. Read from Syntology's graph 2026-09-24; that is when this build read the record, not when the samples ran.

1ran · our draft was wrong
3ran · fixture could not drive it
2ran
1unverified

Licence: 7 of the 7 samples are pointer only, meaning Syntology does not serve that copy's text. This page shows no code text for any sample; each one links to its file in the repository.

Harvested from singlasahil14/improved_l2_robustness. “Ran” means the sample executed on a synthesized input. It does not mean the output is correct, and nothing here reproduces the paper's results. “Honoured” and “violated” refer to a contract Syntology drafted from the code itself; “our draft was wrong” and “fixture could not drive it” are failures of Syntology's instrument, not of the code.

Each sample ends with its code_sha256, Syntology's identity for that exact code. An agent fetches the stored sample with Syntology's MCP tool get_code(code_sha256="…") (how to connect); click an identity to copy that call.

Repository labels, per sample. official repository: The archive marks this repository official for the paper. named in the paper: The archive records that the paper mentions this repository; it is not marked official. community (archive-listed): In the archive's code links for this paper, not marked official and not recorded as mentioned in the paper. found in paper text by Syntology: Syntology found this repository in the paper's own text; whether it is the authors' implementation is not asserted. community: Not in the archive's code links for this paper; a community repository Syntology harvested. Samples from a repository marked official are listed first. Licence labels name the repository's licence as recorded at harvest. “Pointer only” means Syntology does not serve that copy's text, for one of four reasons: no licence file was found; the licence was not identified; the licence is recorded as permissive but that copy's record is not marked cleared; or the licence is outside the permissive list Syntology serves text under (MIT, Apache-2.0, BSD and similar). Some licences outside that list permit redistribution, such as WTFPL, and GPL-3.0 under its conditions; they are simply not on the list. Hover a licence label for the reason. File links open the file on GitHub at the default branch, which may have changed since the harvest.

CRC_Full singlasahil14/improved_l2_robustness/last_layers.py official repository ran · metamorphic tier: deterministic no licence file found · pointer only · 013b1bfe33f55f59 · report
Softplus singlasahil14/improved_l2_robustness/last_layers.py official repository ran · metamorphic tier: deterministic fingerprinted no licence file found · pointer only · f34004f7691b1cad · report
bjorck_orthonormalize singlasahil14/improved_l2_robustness/block_ortho_conv.py official repository ran · fixture could not drive it fingerprinted no licence file found · pointer only · 26fcfa49bfa31422 · report
power_iteration singlasahil14/improved_l2_robustness/block_ortho_conv.py official repository ran · fixture could not drive it fingerprinted no licence file found · pointer only · 596e8fdbd9c6e7cf · report
topk_classes singlasahil14/improved_l2_robustness/last_layers.py official repository ran · fixture could not drive it no licence file found · pointer only · f5993577e4af0b97 · report
transpose_filter singlasahil14/improved_l2_robustness/skew_ortho_conv.py official repository ran · our draft was wrong fingerprinted no licence file found · pointer only · fdef065e9e837d95 · report
orthogonal_matrix singlasahil14/improved_l2_robustness/block_ortho_conv.py official repository unverified no licence file found · pointer only · 296ca28a9ed825a8 · report

Tasks

Adversarial Robustness

Results from the paper archive 2025-07-28

No leaderboard rows for this paper in the archive.

Methods

ConvolutionLinear Layer

Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections