— Peer-reviewed work

Research

ProbeLab team members regularly publish in world-class academic venues. Explorer our articles below.

Year
Any 2025 2024 2022 2021
5 papers

Featured

SIGCOMM '22 Conference Paper ·

Design and Evaluation of IPFS: A Storage Layer for the Decentralized Web

Dennis Trautwein · Aravindh Raman · Gareth Tyson · Ignacio Castro · Will Scott · Moritz Schubotz · Bela Gipp · Yiannis Psaras

Recent years have witnessed growing consolidation of web operations. For example, the majority of web traffic now originates from a few organizations, and even micro-websites often choose to host on large pre-existing cloud infrastructures. In response to this, the "Decentralized Web" attempts to distribute ownership and operation of web services more evenly. This paper describes the design and implementation of the largest and most widely used Decentralized Web platform --- the InterPlanetary File System (IPFS) --- an open-source, content-addressable peer-to-peer network that provides distributed data storage and delivery. IPFS has millions of daily content retrievals and already underpins dozens of third-party applications. This paper evaluates the performance of IPFS by introducing a set of measurement methodologies that allow us to uncover the characteristics of peers in the IPFS network. We reveal presence in more than 2700 Autonomous Systems and 152 countries, the majority of which operate outside large central cloud providers like Amazon or Azure. We further evaluate IPFS performance, showing that both publication and retrieval delays are acceptable for a wide range of use cases. Finally, we share our datasets, experiences and lessons learned.

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2025
SIGMETRICS '26 Conference Paper ·

Multiple Sides of 36 Coins: Measuring Peer-to-Peer Infrastructure Across Cryptocurrencies

Lucianna Kiffer·Lioba Heimbach·Dennis Trautwein·Yann Vonlanthen·Oliver Gasser

Blockchain technologies underpin an expanding ecosystem of decentralized applications, financial systems, and infrastructure. However, the fundamental networking layer that sustains these systems, the peer-to-peer (P2P) layer, of all but the top few ecosystems remains largely opaque. In this paper, we present the first longitudinal, cross-network measurement study of 36 public blockchain networks. Over 9 months (since late 2024), we deployed 15 active crawlers, sourced data from two additional community crawlers, and conducted hourly connectivity probes (e.g., pings and protocol-level handshakes) to observe the evolving state of these networks. Furthermore, by leveraging Ethereum's discovery protocols, we inferred metadata for an additional 19 auxiliary networks that utilize the Ethereum peer discovery protocol. We also explored Internet-wide scans, which only require probing each protocol's default ports with a simple, network-specific payload. This approach allows us to rapidly identify responsive peers across the entire address space without having to implement custom discovery and handshake logic for every blockchain. We validated this method on Bitcoin and similar networks with known ground truth, then applied it to Cardano, which we could not crawl directly. Our study uncovers dramatic variation in network size from under 10 to more than 10,000 active nodes. We quantify trends in IPv4 versus IPv6 usage, analyze autonomous systems and geographic concentration, and characterize churn, diurnal behavior, and the coverage and redundancy of discovery protocols. These findings expose critical differences in network resilience, decentralization, and observability. Beyond characterizing each network, our methodology demonstrates a general framework for measuring decentralized networks at scale. This opens the door for continued monitoring, benchmarking, and more transparent assessments of blockchain infrastructure across diverse ecosystems.

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2024
Usenix Sec '24 Conference Paper ·

Guardians of the Galaxy: Content Moderation in the InterPlanetary File System

Saidu Sokoto·Leonhard Balduf·Dennis Trautwein·Yiluo Wei·Gareth Tyson·Ignacio Castro·Onur Ascigil·George Pavlou·Maciej Korczyński·Björn Scheuermann·Michał Król

The Interplanetary File System (IPFS) is one of the largest platforms in the growing "Decentralized Web". The increasing popularity of IPFS has attracted large volumes of users and content. Unfortunately, some of this content could be considered "problematic". Content moderation is always hard. With a completely decentralized infrastructure and administration, content moderation in IPFS is even more difficult. In this paper, we examine this challenge. We identify, characterize, and measure the presence of problematic content in IPFS (e.g. subject to takedown notices). Our analysis covers 368,762 files. We analyze the complete content moderation process including how these files are flagged, who hosts and retrieves them. We also measure the efficacy of the process. We analyze content submitted to denylist, showing that notable volumes of problematic content are served, and the lack of a centralized approach facilitates its spread. While we identify fast reactions to takedown requests, we also test the resilience of multiple gateways and show that existing means to filter problematic content can be circumvented. We end by proposing improvements to content moderation that result in 227% increase in the detection of phishing content and reduce the average time to filter such content by 43%.

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INFOCOM '24 Conference Paper ·

IPFS in the Fast Lane: Accelerating Record Storage with Optimistic Provide

Dennis Trautwein·Yiluo Wei·Yiannis Psaras·Moritz Schubotz·Ignacio Castro·Bela Gipp

The centralization of web services has raised concerns about critical single points of failure, such as content hosting, name resolution, and certification. To address these issues, the "Decentralized Web" movement advocates for de-centralized alternatives. Distributed Hash Tables (DHTs) have emerged as a key component facilitating this movement, as they offer efficient key/value indexing. The InterPlanetary File System (IPFS) exemplifies this approach by leveraging DHTs for data indexing and distribution. A critical finding of previous studies is that DHT PUT performance for record storage is unacceptably slow, sometimes taking minutes to complete and hindering the adoption of delay-intolerant applications. To address this challenge, this research paper presents three significant contributions. First, we present the design of Optimistic Provide, an approach to accelerate DHT PUT operations in Kademlia-based IPFS networks while maintaining full backward compatibility. Second, we implement and deploy the mechanism and see its usage in the de-facto IPFS deployment, Kubo. Third, we evaluate its effectiveness in the IPFS and Filecoin DHTs. We confirm that we enable sub-second record storage from North America and Europe for 90% of PUT operations while reducing networking overhead by over 40% and maintaining record availability.

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2021
BRAINS '21 Conference Paper ·

Resource Analysis of Ethereum 2.0 Clients

Mikel Cortes·Luca Franceschini·Leonardo Bautista-Gomez

Scalability is a common issue among the most used permissionless blockchains, and several approaches have been proposed to solve this issue. Tackling scalability while preserving the security and decentralization of the network is an important challenge. To deliver effective scaling solutions, Ethereum is on the path of a major protocol improvement called Ethereum 2.0 (Eth2), which implements sharding. As the change of consensus mechanism is an extremely delicate matter, this improvement will be achieved through different phases, the first of which is the implementation of the Beacon Chain. For this, a specification has been developed, and multiple groups have implemented clients to run the new protocol. This work analyzes the resource usage behavior of different clients running as Eth2 nodes, comparing their performance and analyzing differences. Our results show multiple important network perturbations and how different clients react to them. We discuss the differences between Eth2 clients and their limitations.

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