Charmaine Ndolo

Hi, I am Charmaine (she/her) and I am currently working towards my PhD at the Technical University of Dresden under the supervision of Prof. Dr. Florian Tschorsch.

I am a computer scientist by profession with special interests in modern P2P systems. I hold a Master’s from the Humboldt University in Berlin and I am currently pursuing a PhD at the Technical University in Dresden. My main research themes are the performance, security and resilience of blockchain-based P2P networks such as the Lightning network. My work tends to follow quantitative and empirical methods such as network measurements and simulations, while often applying methods from adjacent fields of computer science such as graph theory and game theory. In the past, I have worked on some of the more theoretical aspects of distributed computing such as incentives and analysis of open quorum systems (under Dr. Martin Florian’s supervision). Prior to that, I worked on the analysis of complex graphs as a student assistant in the macsy group.

I am also an amateur baker and often spend my free time trying out new recipes.

As of early 2024, I am a certified football referee in the Dresden football association and regularly officiate local games.

News

Jul, 2024	Our paper “Payment Censorship in the Lightning Network Despite Encrypted Communication” has been accepted to AFT 2024 in Vienna.
Nov, 2023	Subsequent to the chair’s relocation to the Technical University of Dresden, I have joined the Privacy & Security chair at the TU Dresdesn, where I shall continue my PhD.
Jul, 2023	Our paper “On the (Not So) Surprising Impact of Multi-Path Payments on Performance and Privacy in the Lightning Network “ has been accepted to CBT 2023 (co-located with ESORICS 2023) in The Hague.

Latest publication

AFT
Payment Censorship in the Lightning Network Despite Encrypted Communication

Charmaine Ndolo, and Florian Tschorsch

In 6th Conference on Advances in Financial Technologies (AFT 2024), 2024

Abs Bib PDF

The Lightning network (LN) offers a solution to Bitcoin’s scalability limitations by providing fast and private off-chain payments. In addition to the LN’s long known application-level centralisation, recent work has highlighted its centralisation at the network-level which makes it vulnerable to attacks on privacy by malicious actors. In this work, we explore the LN’s susceptibility to censorship by a network-level actor such as a malicious autonomous system. We show that a network-level actor can identify and censor all payments routed via their network by just examining the packet headers. Our results indicate that it is viable to accurately identify LN messages despite the fact that all inter-peer communication is end-to-end encrypted. Additionally, we describe how a network-level observer can determine a node’s role in a payment path based on timing, direction of flow and message type, and demonstrate the approach’s feasibility using experiments in a live instance of the network. Simulations of the attack on a snapshot of the Lightning mainnet suggest that the impact of the attack varies from mild to potentially dramatic depending on the adversary and type of payments that are censored. We analyse countermeasures the network can implement and come to the conclusion that an adequate solution comprises constant message sizes as well as dummy traffic.
@inproceedings{ndolo2024payment, author = {Ndolo, Charmaine and Tschorsch, Florian}, title = {{Payment Censorship in the Lightning Network Despite Encrypted Communication}}, booktitle = {6th Conference on Advances in Financial Technologies (AFT 2024)}, pages = {12:1--12:24}, series = {Leibniz International Proceedings in Informatics (LIPIcs)}, isbn = {978-3-95977-345-4}, issn = {1868-8969}, year = {2024}, volume = {316}, publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik}, url = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.AFT.2024.12}, doi = {10.4230/LIPIcs.AFT.2024.12}, }