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congratulations to ASM Rizvi for his PhD

I would like to congratulate Dr. ASM Rizvi for defending his PhD at the University of Southern California in June 2024 and completing his doctoral dissertation “Mitigating Attacks that Disrupt Online Services Without Changing Existing Protocols”.

From the dissertation abstract:

ASM Rizvi and John Heidemann, after Rizvi's PhD defense.

Service disruption is undesirable in today’s Internet connectivity due to its impacts on enterprise profits, reputation, and user satisfaction. We describe service disruption as any targeted interruptions caused by malicious parties in the regular user-to-service interactions and functionalities that affect service performance and user experience. In this thesis, we propose new methods that tackle service disruptive attacks using measurement without changing existing Internet protocols. Although our methods do not guarantee defense against all the attack types, our example defense systems prove that our methods generally work to handle diverse attacks. To validate our thesis, we demonstrate defense systems against three disruptive attack types. First, we mitigate Distributed Denial-of-Service (DDoS) attacks that target an online service. Second, we handle brute-force password attacks that target the users of a service. Third, we detect malicious routing detours to secure the path from the users to the server. We provide the first public description of DDoS defenses based on anycast and filtering for the network operators. Then, we show the first moving target defense utilizing IPv6 to defeat password attacks. We also demonstrate how regular observation of latency helps cellular users, carriers, and national agencies to find malicious routing detours. As a supplemental outcome, we show the effectiveness of measurements in finding performance issues and ways to improve using existing protocols. These examples show that our idea applies to different network parts, even if we may not mitigate all the attack types.

Rizvi’s PhD work was supported by the U.S. Department of Homeland Security’s HSARPA Cyber Security Division (HSHQDC-17-R-B0004-TTA.02-0006-I, PAADDOS) in a joint project with the Netherlands Organisation for scientific research (4019020199), the U.S. National Science Foundation (grant NSF OAC-1739034, DDIDD; CNS-2319409, PIMAWAT; CRI-8115780, CLASSNET; CNS-1925737, DIINER ) and U.S. DARPA (HR001120C0157, SABRES), and Akamai.

Most data from his papers is available at no cost from ANT; please see specific publications for details.

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USC/Viterbi and ISI news about “Anycast Agility” paper

USC Viterbi and ISI both posted a news article about our paper “Anycast Agility: Network Playbooks to Fight DDoS”.

Please see our blog entry for the abstract and the full technical paper for the real details, but their posts are very accessible. And with the hacker in the hoodie, you know it’s serious :-)

The canonical hacker in the hoodie, testifying to serious security work.
Categories
Internet Papers Publications Software releases

new paper “Chhoyhopper: A Moving Target Defense with IPv6” at NDSS MADWeb Workshop 2022

On April 24, 2022 we will publish a new paper titled “Chhoyhopper: A Moving Target Defense with IPv6” by A S M Rizvi and John Heidemann at the 4th Workshop on Measurements, Attacks, and Defenses for the Web (MADWeb 2022), co-located with NDSS. We provide Chhoyhopper as an open-source tool for SSH and HTTPS—try it out!

From the abstract:

Services on the public Internet are frequently scanned, then subject to brute-force password attempts and Denial-of-Service (DoS) attacks. We would like to run such services stealthily, where they are available to friends but hidden from adversaries. In this work, we propose a discovery-resistant moving target defense named “Chhoyhopper” that utilizes the vast IPv6 address space to conceal publicly available services. The client meets the server at an IPv6 address that changes in a pattern based on a shared, pre-distributed secret and the time of day. By hopping over a /64 prefix, services cannot be found by active scanners, and passively observed information is useless after two minutes. We demonstrate our system with the two important applications—SSH and HTTPS, and make our system publicly available.

Client and server interaction in Chhoyhopper. A Client with the right secret key can only get access into the system.

Thanks: A S M Rizvi and John Heidemann’s work on this paper is supported, in part, by the DHS HSARPA Cyber Security Division via contract number HSHQDC-17-R-B0004-TTA.02-0006-I (PAADDoS), and by DARPA under Contract No. HR001120C0157 (SABRES). Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of NSF or DARPA. We thank Rayner Pais who prototyped an early version of Chhoyhopper and version in IPv4 hopping over ports.

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Anycast BGP Internet

new paper “Anycast Agility: Network Playbooks to Fight DDoS” at USENIX Security Symposium 2022

We will publish a new paper titled “Anycast Agility: Network Playbooks to Fight DDoS” by A S M Rizvi (USC/ISI), Leandro Bertholdo (University of Twente), João Ceron (SIDN Labs), and John Heidemann (USC/ISI) at the 31st USENIX Security Symposium in Aug. 2022.

A sample anycast playbook for a 3-site anycast deployment. Different routing configurations provide different traffic mixes. From [Rizvi22a, Table 5].

From the abstract:

IP anycast is used for services such as DNS and Content Delivery Networks (CDN) to provide the capacity to handle Distributed Denial-of-Service (DDoS) attacks. During a DDoS attack service operators redistribute traffic between anycast sites to take advantage of sites with unused or greater capacity. Depending on site traffic and attack size, operators may instead concentrate attackers in a few sites to preserve operation in others. Operators use these actions during attacks, but how to do so has not been described systematically or publicly. This paper describes several methods to use BGP to shift traffic when under DDoS, and shows that a response playbook can provide a menu of responses that are options during an attack. To choose an appropriate response from this playbook, we also describe a new method to estimate true attack size, even though the operator’s view during the attack is incomplete. Finally, operator choices are constrained by distributed routing policies, and not all are helpful. We explore how specific anycast deployment can constrain options in this playbook, and are the first to measure how generally applicable they are across multiple anycast networks.

Dataset used in this paper are listed at https://ant.isi.edu/datasets/anycast/anycast_against_ddos/index.html, and the software used in our work is at https://ant.isi.edu/software/anygility. They are provided as part of Call for Artifacts.

Acknowledgments: A S M Rizvi and John Heidemann’s work on this paper is supported, in part, by the DHS HSARPA Cyber Security Division via contract number HSHQDC-17-R-B0004-TTA.02-0006-I. Joao Ceron and Leandro Bertholdo’s work on this paper is supported by Netherlands Organisation for scientific research (4019020199), and European Union’s Horizon 2020 research and innovation program (830927). We would like to thank our anonymous reviewers for their valuable feedback. We are also grateful to the Peering and Tangled admins who allowed us to run measurements. We thank Dutch National Scrubbing Center for sharing DDoS data with us. We also thank Yuri Pradkin for his help to release our datasets.

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Papers Publications

New paper “Bidirectional Anycast/Unicast Probing (BAUP): Optimizing CDN Anycast” at IFIP TMA 2020

We published a new paper “Bidirectional Anycast/Unicast Probing (BAUP): Optimizing CDN Anycast” by Lan Wei (University of Southern California/ ISI), Marcel Flores (Verizon Digital Media Services), Harkeerat Bedi (Verizon Digital Media Services), John Heidemann (University of Southern California/ ISI) at Network Traffic Measurement and Analysis Conference 2020.

From the abstract:

IP anycast is widely used today in Content Delivery Networks (CDNs) and for Domain Name System (DNS) to provide efficient service to clients from multiple physical points-of-presence (PoPs). Anycast depends on BGP routing to map users to PoPs, so anycast efficiency depends on both the CDN operator and the routing policies of other ISPs. Detecting and diagnosing
inefficiency is challenging in this distributed environment. We propose Bidirectional Anycast/Unicast Probing (BAUP), a new approach that detects anycast routing problems by comparing anycast and unicast latencies. BAUP measures latency to help us identify problems experienced by clients, triggering traceroutes to localize the cause and suggest opportunities for improvement. Evaluating BAUP on a large, commercial CDN, we show that problems happens to 1.59% of observers, and we find multiple opportunities to improve service. Prompted by our work, the CDN changed peering policy and was able to significantly reduce latency, cutting median latency in half (40 ms to 16 ms) for regions with more than 100k users.

The data from this paper is publicly available from RIPE Atlas, please see paper reference for measurement IDs.

Categories
Announcements Projects

new project “Plannning for Anycast as Anti-DDoS” (PAADDoS)

We are happy to announce a new project Plannning for Anycast as Anti-DDoS (PAADDoS).

The PAADDoS project’s goal is to defend against large-scale DDoS attacks by making anycast-based capacity more effective than it is today.

We will work toward this goal by (1) developing tools to map anycast catchments and baseline load, (2) develop methods to plan changes and their effects on catchments, (3) develop tools to estimate attack load and assist anycast reconfiguration during an attack. and (4) evaluate and integration of these tools with traditional DoS defenses.

We expect these innovations to improve service resilience in the face of DDoS attacks. Our tools will improve anycast agility during an attack, allowing capacity to be used effectively.

PAADDoS is a joint effort of the ANT Lab involving USC/ISI (PI: John Heidemann) and the Design and Analysis of Communication Systems group at the University of Twente (PI: Aiko Pras).

PAADDoS is supported by the DHS HSARPA Cyber Security Division via contract number HSHQDC-17-R-B0004-TTA.02-0006-I, and by NWO.