arXiv Machine Learning

Unknown-Traffic Detection, Calibration and Shortcut Reliance in Distilled Encrypted-Traffic Classifiers over One Year

The study investigates what knowledge a student model inherits from its teachers beyond accuracy when using knowledge distillation for encrypted‑traffic classification. By distilling a 101k‑parameter student from two teachers of equal accuracy but different construction, the authors test ten hypotheses over a year of real TLS traffic, finding that unknown‑traffic detection and shortcut reliance can transfer depending on temperature settings and model size, while other abilities do not. The results show that distillation can propagate teacher habits, but some inherited capabilities can also be achieved without a teacher.

arXiv AI
6d ago

Where LLM Graders Succeed and Break: Evidence from Two Computer-Science Exams

The study evaluates large language model (LLM) graders on two computer‑science exams, testing 171 configurations of closed‑ and open‑weights models. While the best LLM configuration achieved a mean absolute error of 1.64/35—better than the 2.61/35 error between two human graders—its performance was highly sensitive to the prompt. A short "strict grader" preamble caused most open‑weight models to exceed acceptable error thresholds or stop grading entirely, whereas fine‑tuning with a single LoRA adapter restored parity with human graders and reduced sensitivity to harsh prompts.

By Ali Habibullah, Yazan Alshoibi, Mohammad Alshiekh, Salman Khan, Naeemullah Khan
arXiv AI
Sep 24

Multi-View Fusion for Encrypted C2 Detection: A Leakage-Controlled Measurement Study of Evaluation Pitfalls

The paper evaluates the common assumption that combining flow statistics and TLS handshake fingerprints improves encrypted command-and-control detection. Using 17,577 TLS flows from 62 real Cobalt Strike captures, the authors show that data leakage and preprocessing choices inflate performance metrics, revealing that the true benefit of multi-view fusion is minimal (0.022 F1). They also uncover that many captures contain only benign traffic and that class imbalance is an artifact of analysis rather than a real feature of the task.

By Hoang-Huy Nguyen-Huu, Van-Tri Phan, Khuong Nguyen-An
arXiv Machine Learning
Sep 22

A Shared Learning Rate Is Not a Neutral Control in Selective On-Policy Distillation

The paper investigates selective on‑policy distillation, where a student model is trained only on token positions chosen by a selector. It demonstrates that the commonly used shared learning rate is not neutral: performance varies significantly with the learning rate for different selectors, leading to inconsistent comparisons. The authors attribute this selector‑rate entanglement to the selection process itself and recommend reporting the full arm‑by‑rate matrix for fair evaluation.

By Chencheng Zhu
arXiv Machine Learning
Jul 14

Reference-Based Distillation Detection in LLMs

arXiv:2607. 09692v1 Announce Type: new Abstract: Model distillation -- training on outputs from stronger third-party models -- is widely used to boost performance, but raises concerns about unfair advantages and policy violations.

By Rajat Rawat, Sizhe Chen, Akshay Anand, Michael Duan, Bob Rotsted, Sewon Min
arXiv Machine Learning
Sep 17

TwinMark: A Unified Watermark for Provable Survival Under Feature and Logit Distillation

TwinMark is a watermarking scheme that embeds a single SHAKE128 secret into a vision model using two complementary linear functionals of model-output summaries: a covariance projector (cov‑Feat) and a class‑conditional Fisher‑aligned linear carrier (cc‑FALC). These readouts cover both classifier APIs attacked by KL knowledge distillation and representation‑only hosts attacked by feature‑matching distillation, each providing a teacher‑measurable a posteriori certificate. Across 13 attacks on datasets such as CIFAR‑10, CIFAR‑100, and Mini‑ImageNet, TwinMark remains detectable on every post‑attack model that retains task utility, survives cross‑architecture distillation onto ResNet‑18/50, VGG‑16, and MobileNet‑V3, and can be ported to GNSS few‑shot, VOC detection, ISIC segmentation, and STL‑10 SimCLR.

By Redwanul Karim, Tobias Feigl, Christopher Mutschler, Felix Ott
arXiv Machine Learning
Sep 24

When Accuracy Gaps Fail to Certify: Auditing Cross-Domain Recalibration of LLM Judges

The study examines whether accuracy gaps between source and target tasks can certify the failure of scalar recalibration maps for large language model judges. Across thirteen judges, two generators, eight domains, and 1,176 transfers, the accuracy gap only provides a weak lower bound on target calibration error and can predict opposite outcomes. Even with a finite‑sample lower certificate, the method shows low power (0.13) and does not reliably indicate when recalibration will fail.

By Fariya Afrin, Ibne Farabi Shihab