Internet blackouts are challenging environments for anonymity and censorship resistance. Existing popular anonymity networks (e.g., Freenet, I2P, Tor) rely on Internet connectivity to function, making them impracticable during such blackouts. In such a setting, mobile ad-hoc networks can provide connectivity, but prior communication protocols for ad-hoc networks are not designed for anonymity and attack resilience. We address this need by designing, implementing, and evaluating Moby, a blackout-resistant anonymity network for mobile devices. Moby provides end-to-end encryption, forward secrecy and sender-receiver anonymity. It features a bi-modal design of operation, using Internet connectivity when available and ad-hoc networks during blackouts. During periods of Internet connectivity, Moby functions as a regular messaging application and bootstraps information that is later used in the absence of Internet connectivity to achieve secure anonymous communications. Moby incorporates a model of trust based on users’ contact lists, and a trust establishment protocol that mitigates flooding attacks. We perform an empirically informed simulation-based study based on cellphone traces of 268,596 users over the span of a week for a large cellular provider to determine Moby’s feasibility and present our findings. Last, we implement and evaluate the Moby client as an Android app.
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Detecting and Measuring In-The-Wild DRDoS Attacks at IXPs
Distributed reflective denial of service (DRDoS) attacks are a popular choice among adversaries. In fact, one of the largest DDoS attacks ever recorded, reaching a peak of 1.3 Tbps against GitHub, was a memcached-based DRDoS attack. More recently, a record-breaking 2.3 Tbps attack against Amazon AWS was due to a CLDAP-based DRDoS attack. Although reflective attacks have been known for years, DRDoS attacks are unfortunately still popular and largely unmitigated.
In this paper, we measure in-the-wild DRDoS attacks as observed from a large Internet exchange point (IXP) and provide a number of security-relevant insights. To enable our measurements, we first developed IXmon, an open-source DRDoS detection system specifically designed for deployment at large IXP-like network connectivity providers and peering hubs. We deployed IXmon at Southern Crossroads (SoX), an IXP-like hub that provides both peering and upstream Internet connectivity services to more than 20 research and education (R&E) networks in the South-East United States. In a period of about 21 months, IXmon detected more than 900 DRDoS attacks towards 31 different victim ASes. An analysis of the real-world DRDoS attacks detected by our system shows that most DRDoS attacks are short lived, lasting only a few minutes, but that large-volume, long-lasting, and highly-distributed attacks against R&E networks are not uncommon. We then use the results of our analysis to discuss possible attack mitigation approaches that can be deployed at the IXP level, before the attack traffic overwhelms the victim’s network bandwidth.
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- Award ID(s):
- 1741608
- PAR ID:
- 10303439
- Date Published:
- Journal Name:
- International Conference on Detection of Intrusions and Malware, and Vulnerability Assessment
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1007/978-3-030-80825-9_3
