Yarin Perry (The Hebrew University of Jerusalem), Neta Rozen-Schiff (The Hebrew University of Jerusalem), Michael Schapira (The Hebrew University of Jerusalem)

The Network Time Protocol (NTP) synchronizes time across computer systems over the Internet and plays a crucial role in guaranteeing the correctness and security of many Internet applications. Unfortunately, NTP is vulnerable to so called time shifting attacks. This has motivated proposals and standardization efforts for authenticating NTP communications and for securing NTP textit{clients}. We observe, however, that, even with such solutions in place, NTP remains highly exposed to attacks by malicious textit{timeservers}. We explore the implications for time computation of two attack strategies: (1) compromising textit{existing} NTP timeservers, and (2) injecting textit{new} timeservers into the NTP timeserver pool. We first show that by gaining control over fairly few existing timeservers, an textit{opportunistic} attacker can shift time at state-level or even continent-level scale. We then demonstrate that injecting new timeservers with disproportionate influence into the NTP timeserver pool is alarmingly simple, and can be leveraged for launching both large-scale textit{opportunistic} attacks, and strategic, textit{targeted} attacks. We discuss a promising approach for mitigating such attacks.

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Towards Understanding and Detecting Cyberbullying in Real-world Images

Nishant Vishwamitra (University at Buffalo), Hongxin Hu (University at Buffalo), Feng Luo (Clemson University), Long Cheng (Clemson University)

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Evading Voltage-Based Intrusion Detection on Automotive CAN

Rohit Bhatia (Purdue University), Vireshwar Kumar (Indian Institute of Technology Delhi), Khaled Serag (Purdue University), Z. Berkay Celik (Purdue University), Mathias Payer (EPFL), Dongyan Xu (Purdue University)

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FLTrust: Byzantine-robust Federated Learning via Trust Bootstrapping

Xiaoyu Cao (Duke University), Minghong Fang (The Ohio State University), Jia Liu (The Ohio State University), Neil Zhenqiang Gong (Duke University)

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FlowLens: Enabling Efficient Flow Classification for ML-based Network Security...

Diogo Barradas (INESC-ID, Instituto Superior Técnico, Universidade de Lisboa), Nuno Santos (INESC-ID, Instituto Superior Técnico, Universidade de Lisboa), Luis Rodrigues (INESC-ID, Instituto Superior Técnico, Universidade de Lisboa), Salvatore Signorello (LASIGE, Faculdade de Ciências, Universidade de Lisboa), Fernando M. V. Ramos (INESC-ID, Instituto Superior Técnico, Universidade de Lisboa), André Madeira (INESC-ID, Instituto Superior Técnico, Universidade de…

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