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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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Presentations Publications

new poster “Chhoyhopper: A Moving Target Defense with IPv6” at ACSAC-2021

We published a new poster titled “Chhoyhopper: A Moving Target Defense with IPv6” by A S M Rizvi (USC/ISI) and John Heidemann (USC/ISI) at ACSAC-2021. We presented our poster virtually using a video. We provide chhoyhopper as open source–try it out!

Client and server interaction in Chhoyhopper. A client with a shared secret key can only get access to the system.

From the abstract:

Services on the public Internet are frequently scanned, then subject to brute-force and denial-of-service attacks. We would like to run such services stealthily, available to friends but hidden from adversaries. In this work, we propose a moving target defense named “Chhoyhopper” that utilizes the vast IPv6 address space to conceal publicly available services. The client and server hop to different IPv6 addresses 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.

This work is supported, in part, by DHS HSARPA Cyber Security Division via contract number HSHQDC-17-R-B0004-TTA.02-0006-I, and by DARPA under Contract No. HR001120C0157.