background noise
- North America > United States > Pennsylvania > Northampton County > Bethlehem (0.04)
- North America > United States > Maryland > Prince George's County > College Park (0.04)
- Asia > China > Jilin Province (0.04)
RECTor: Robust and Efficient Correlation Attack on Tor
Wu, Binghui, Divakaran, Dinil Mon, Csikor, Levente, Gurusamy, Mohan
Tor is a widely used anonymity network that conceals user identities by routing traffic through encrypted relays, yet it remains vulnerable to traffic correlation attacks that deanonymize users by matching patterns in ingress and egress traffic. However, existing correlation methods suffer from two major limitations: limited robustness to noise and partial observations, and poor scalability due to computationally expensive pairwise matching. To address these challenges, we propose RECTor, a machine learning-based framework for traffic correlation under realistic conditions. RECTor employs attention-based Multiple Instance Learning (MIL) and GRU-based temporal encoding to extract robust flow representations, even when traffic data is incomplete or obfuscated. These embeddings are mapped into a shared space via a Siamese network and efficiently matched using approximate nearest neighbor (aNN) search. Empirical evaluations show that RECTor outperforms state-of-the-art baselines such as DeepCorr, DeepCOFFEA, and FlowTracker, achieving up to 60% higher true positive rates under high-noise conditions and reducing training and inference time by over 50%. Moreover, RECTor demonstrates strong scalability: inference cost grows near-linearly as the number of flows increases. These findings reveal critical vulnerabilities in Tor's anonymity model and highlight the need for advanced model-aware defenses.
- Asia > Singapore (0.15)
- North America > United States (0.04)
PCA++: How Uniformity Induces Robustness to Background Noise in Contrastive Learning
Wu, Mingqi, Sun, Qiang, Yang, Yi
High-dimensional data often contain low-dimensional signals obscured by structured background noise, which limits the effectiveness of standard PCA. Motivated by contrastive learning, we address the problem of recovering shared signal subspaces from positive pairs, paired observations sharing the same signal but differing in background. Our baseline, PCA+, uses alignment-only contrastive learning and succeeds when background variation is mild, but fails under strong noise or high-dimensional regimes. To address this, we introduce PCA++, a hard uniformity-constrained contrastive PCA that enforces identity covariance on projected features. PCA++ has a closed-form solution via a generalized eigenproblem, remains stable in high dimensions, and provably regularizes against background interference. We provide exact high-dimensional asymptotics in both fixed-aspect-ratio and growing-spike regimes, showing uniformity's role in robust signal recovery. Empirically, PCA++ outperforms standard PCA and alignment-only PCA+ on simulations, corrupted-MNIST, and single-cell transcriptomics, reliably recovering condition-invariant structure. More broadly, we clarify uniformity's role in contrastive learning, showing that explicit feature dispersion defends against structured noise and enhances robustness.
- North America > Canada > Ontario > Toronto (0.14)
- North America > Canada > Quebec > Montreal (0.04)
- Europe > Netherlands > South Holland > Leiden (0.04)
- (3 more...)
- Asia > China > Zhejiang Province > Hangzhou (0.05)
- Africa > Senegal > Kolda Region > Kolda (0.04)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- North America > United States > Massachusetts > Middlesex County > Cambridge (0.04)
- Europe > Italy > Calabria > Catanzaro Province > Catanzaro (0.04)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- South America > Chile > Santiago Metropolitan Region > Santiago Province > Santiago (0.04)
- North America > United States > Massachusetts > Middlesex County > Cambridge (0.04)
- (4 more...)
Explainable Disentanglement on Discrete Speech Representations for Noise-Robust ASR
Gopal, Shreyas, Anshul, Ashutosh, Li, Haoyang, Yeo, Yue Heng, Liu, Hexin, Chng, Eng Siong
Discrete audio representations are gaining traction in speech modeling due to their interpretability and compatibility with large language models, but are not always optimized for noisy or real-world environments. Building on existing works that quantize Whisper embeddings for speech-to-unit modeling, we propose disentangling semantic speech content from background noise in the latent space. Our end-to-end model separates clean speech in the form of codebook tokens, while extracting interpretable noise vectors as quantization residue which are supervised via a lightweight classifier. We show that our approach improves alignment between clean/noisy speech and text, producing speech tokens that display a high degree of noiseinvariance, and improves ASR performance. Keeping Whisper frozen, we show an 82% reduction in error rate compared to Whisper, and 35% improvement over baseline methods on the VBDemand test set. Further analyses show that the learned token space generalizes well to both seen and unseen acoustic conditions.