Networking · Cross-listed from cs.LG
User-Level Handover Decision Making Based on Machine Learning Approaches
João Lima, Alvaro Medeiros, Eduardo Aguiar et al. (+2 more)
This letter covers a broad comparison of methods for classification and regression applications for a user-level handover decision making in scenarios with adverse propagation conditions involving buildings, coverage holes, and shadowing effects. The simulation campaigns are based on network simulator ns-3. The comparison encompasses classical machine learning approaches, such as KNN, SVM, and neural networks, but also state-of-the-art fuzzy logic systems and latter boosting machines. The results indicate that SVM and MLP are the most suitable for the classification of the best handover target, although fuzzy system SOFL can perform similarly with lower processing time. Additionally, for the download time estimation, LightGBM provides the smallest error with short processing time, even in hard propagation scenarios.
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All authors João Lima, Alvaro Medeiros, Eduardo Aguiar, Vicente Angelo de Sousa Junior, Tarciana Guerra
Networking · Cross-listed from cs.CR
Tick-Tock on the Open Fronthaul: Securing Synchronization in O-RAN
Yiwei Zhang, Enrico Pisanti, Imtiaz Karim et al. (+2 more)
The Precision Time Protocol (PTP) provides the time and phase synchronization required by disaggregated Open
Radio Access Networks (O-RAN). Yet, in current open fronthaul deployments, PTP traffic lacks mandatory authentication and integrity protection, leaving synchronization vulnerable to spoofing, replay, and delay manipulation attacks that can degrade
radio access performance. Existing protections are poorly suited to this setting: they either add excessive latency, do not support multicast dissemination efficiently, or fail to contain key exposure under partially trusted RUs. This paper analyzes the security risks of unprotected O-RAN PTP and develops a threat model for open fronthaul deployments. We then introduce PRTESLA-C, a lightweight synchronization protection mechanism that combines per-round delayed key disclosure with ASCON-based message authentication. PRTESLA-C uses an apply-then-verify-and-correct paradigm: timing samples are applied immediately to preserve real-time control, verified after key disclosure, and removed from persistent synchronization state if authentication fails. This design maintains sub-microsecond synchronization accuracy, provides strong protection against spoofing and replay, and bounds the impact of delay manipulation with minimal computational and latency overhead.
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All authors Yiwei Zhang, Enrico Pisanti, Imtiaz Karim, Subangkar Karmaker Shanto, Elisa Bertino
Networking
Semantics Delivery Network: Rethinking Web Retrieval Infrastructure for LLM Agents
Peichun Hua and Yunming Xiao
Large
language models (LLMs) increasingly rely on external sources when answering questions that require proprietary information or up-to-date live web content, through both traditional single-shot
retrieval-augmented generation (RAG) and multi-turn agentic RAG. Yet today's web infrastructure is still built for human clients. Given a query, current search services return a list of URLs and snippets ranked for generic relevance; content delivery networks (CDNs) cache URL-addressed objects (texts, images,
videos, etc.) without knowing which passage an
agent needs. LLMs, in contrast, consume short, semantically coherent passages, hereafter "chunks", selected for downstream task utility rather than similarity alone, and may retrieve statefully across
reasoning turns. Uncoordinated
agents also repeat search, data acquisition, and semantic processing, duplicating work that could be shared. We argue that semantic chunk
retrieval should become a first-class network-delivery abstraction. We propose Semantics Delivery Network (SemDN): an origin-authorized, hierarchical edge substrate that indexes, searches, and smart-caches web content at chunk granularity. SemDN serves
agents on behalf of participating websites, amortizes data acquisition and processing across
agents, and supports tenant-specific
retrieval policies. Because, unlike URL caching, semantic
retrieval provides no explicit miss signal, SemDN must estimate when its enrolled corpus may be incomplete or stale and trigger scoped discovery or refresh. It raises open questions about shareable
retrieval state, hierarchical caching, coverage risk, and deployment. Our preliminary probes reveal a large gap between page content processed and chunks consumed, substantial task-local reuse, and higher answer quality per context
token from chunk delivery.
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Networking · Cross-listed from cs.CR
Provisional Reachability: Containing Agents by Making Every Crossing Revocable
Yoshiaki Takashita
A companion paper found that what a defender must block over time has units: bits per period [Takashita, 2026a]. This paper sets it. Hold every crossing in escrow for one period, audit each held item independently with probability r, and revoke the window if any audit catches something. An adversary crossing k times, each carrying c bits, expects kc(1-r)^k, maximised at k* = 1/ln(1/(1-r)), a bound of L(r) ~ c/(er) per window. The bound is a supremum over the adversary's choice, so the scheme may be public; simulation matches it to 7.7 standard errors. It is a rate, not a total: escrow alone still lets the secret assemble in every run. But if the secret decays at a fraction mu of held bits per period, holdings converge to g/mu at any horizon, so an L-bit secret is unreachable once mu > g/L – an error threshold in Eigen's sense, sharp where the closed form puts it (100% of runs assemble at 0.9mu*, 0% at 2mu*, over 20,000 windows). Deception that needs the adversary to reason badly fails: a surface whose names lie left accuracy at 18 of 18, and 100% at three reader strengths. Withholding reference works, and differently: no reader would commit at all. Keying the entry points hides 0.10 bits of what a module does; keying the denotation hides 2.64 of 3.00 at chance accuracy, while 100% of readers still call it ordinary Python. Variance must be removed from the audit rate, where loot is convex in r, and added to the activation budget, where survival is multiplicative: extinction 70% to 100% at a fixed mean. End to end the stack takes the leak from 100,000 to 59 bits, a factor of 1,704, leaving 12% of legitimate work standing; keying the window to the caller restores that to 100% at no cost in leakage, at the price of a bound that is per principal. Of 65 read-only tools, escrow leaves 2,400 bits per call: a factor of 10, not infinity.
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Networking
A Multi-Cloud View of Internet Background Radiation
Nils Kempen, Ricky K. P. Mok, Bernhard Degen et al. (+2 more)
As services are increasingly centralized in public clouds, understanding the nature of Internet Background Radiation (IBR) hitting these particular environments is an important part of understanding their overall security posture. Classical network
telescopes, long the cornerstone of IBR research, face hurdles here: their surface area is shrinking, and their well-known address ranges are easily avoided. We present a multi-cloud view of IBR in this paper. We deploy a passive, distributed network
telescope with 336 IPs across five major cloud providers. We compare traffic from our cloud
telescope with data from two classical
telescopes, a large well-known (/9 + /10) and a small unknown /16, to analyze observational biases. To enable a fair comparison across very different
telescope sizes, we tune a scan detection
algorithm to determine appropriate thresholds. Our findings reveal that IBR in the cloud is strongly provider-dependent rather than geography-dependent, highlighting the necessity of multi-cloud deployments for comprehensive visibility of IBR in the cloud. Our cloud
telescope also captures a distinct set of scanners, confirming that scanning activity is not uniform across the IPv4 space, and we confirm that small, distributed
telescopes are ill-suited for observing random events like DDoS backscatter. Our work underscores that monitoring must evolve beyond classical
telescopes to include diverse, multi-cloud vantage points to accurately capture IBR.
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All authors Nils Kempen, Ricky K. P. Mok, Bernhard Degen, Syed Mujtaba Jafri, Ralph Holz
Networking · Cross-listed from eess.SP
Secure RIS-Aided Multicasting: Globally Optimal Beam Management and Discrete-Phase RIS Configuration
Luis F. Abanto-Leon and Setareh Maghsudi
Reconfigurable intelligent surfaces (RISs) are poised to revolutionize wireless multicasting by enabling extended coverage and reliable operation in obstructed environments. These benefits, however, can be undermined by security vulnerabilities arising from practical deployment factors. This work addresses three such critical factors, (i) the discrete nature of RIS phase shifts, (ii) the presence of colluding eavesdroppers, and (iii) the inefficiency of static illumination beams, each threatening security if not properly accounted for in system design. To mitigate these issues, we formulate a joint resource allocation problem that minimizes the wiretap signal-to-noise ratio (SNR) across all eavesdroppers by co-optimizing the RIS configuration and the base station (BS) beam management. This yields a complex, nonconvex mixed-integer nonlinear program (MINLP), which we equivalently reformulate into a tractable mixed-integer quadratically constrained program (MIQCP) solvable to global optimality. Numerical results confirm that the proposed scheme significantly bolsters security, suppressing the wiretap SNR by up to 58% compared to existing baselines.
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Networking
Pattern-Aware Virtual Network Embedding Optimization for Cloud Data Centers
Binquan Guo, Zhou Zhang, Junfeng Zhai et al. (+3 more)
The network virtualization (NV) technology has enabled the sharing of multiple resources among virtual networks (VNs) in cloud data centers. One of the key challenges is to allocate resources in real-time for virtual network request (VNR), which is known as online virtual network
embedding (VNE). However, the existing online VNE methods do not exploit the multi-dimensional complementary relationship among diverse VNRs, resulting in the fragmentation and waste of substrate resources. In this paper, we propose the pattern matching based online VNE approach by constructing appropriate matching rules among observed patterns to maximize resources utilization. We devise the clustering based VNRs quantization method and conduct rigorous study on the pattern combination filtering problem. Then, we utilize the column generation to solve it and construct the pattern matching rules. Based on the rules, we propose an online pattern matching VNE
algorithm with linear worst-case complexity. Evaluation on a 106-server testbed using Alibaba production cluster trace
dataset shows that our
algorithm achieves close-to-offline performance and more accepted workloads that outperforms traditional designs by 25%-30%.
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All authors Binquan Guo, Zhou Zhang, Junfeng Zhai, Zheng Zhang, Marie Siew, Zehui Xiong
Networking
Locating and Enumerating Anycast: a Comparison of Two Approaches
Remi Hendriks, Tim Betzer, Ben Du et al. (+3 more)
Anycast allows for providing services from multiple, geographically distant Points of Presence (PoPs), using a single IP address, to, e.g., improve resilience. Due to its opaqueness, it is often unknown which addresses are provisioned using anycast and, if so, where the PoPs are located. As anycast is widely used for critical Internet infrastructures (e.g., the DNS) efforts have been made to map anycast deployments. The current state-of-the-art mapping technique, iGreedy, relies on latency-based measurements, and is adversely affected by noise caused by, e.g., network processing delays. Previous work has shown that traceroute can alternatively be used to detect anycast. As traceroute reveals the hops a packet traverses, it may also be used to locate sites using geolocation data for hops near the anycast PoPs. This paper is the first to assess the performance of the traceroute-based approach at scale, by targeting 14k prefixes from an anycast census. Using ground truth we show traceroute achieves a slight increase in enumeration and geolocation precision over iGreedy. However, it suffers from overestimating the number of PoPs and incurs a 4 times increase in probing cost, making it unattractive for anycast censuses.
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All authors Remi Hendriks, Tim Betzer, Ben Du, Raffaele Sommese, Mattijs Jonker, Roland van Rijswijk-Deij
Networking · Cross-listed from cs.CR
X-SPUR: Explainable Surprisal-Based Protocol-Aware Unsupervised Reasoning for Automotive Ethernet Intrusion Detection
Jisoo Kim and Seonghoon Jeong
Automotive Ethernet carries heterogeneous multi-protocol traffic in modern in-vehicle networks, where labeled attack data are rarely available and the strongest prior unsupervised detector still relies on handcrafted traffic features. This article presents X-SPUR, an explainable, surprisal-based, protocol-aware unsupervised
reasoning framework that instead represents raw packet fields as
token sequences, learns benign traffic patterns through causal
language modeling, and detects anomalies from per-
token cross-
entropy surprisal. To incorporate temporal context, we introduce a bimodal fusion architecture that combines payload-
token embeddings with inter-packet timing through additive fusion and a Hadamard interaction. To handle the heterogeneous score distributions of different protocol families, we further propose a dual top-$k$% per-protocol $Z$-score calibration that jointly captures moderately distributed and sparse anomaly signatures. On the TOW-IDS
dataset, X-SPUR achieves an AUC of 0.9987. This is marginally higher than the 0.9969 reported for AERO. X-SPUR also eliminates handcrafted feature engineering. We train a separate CarDS model using the same architecture and training hyperparameters. This model retains strong performance on the second automotive Ethernet
dataset. Beyond detection, per-
token surprisal provides fine-grained explainability by attributing anomaly scores to specific protocol fields, supporting interpretable security analysis in heterogeneous in-vehicle networks.
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