Elias Rohrer's research while affiliated with Technische Universität Berlin and other places

Publications (15)

Preprint
Full-text available
Nodes in the Lightning Network synchronise routing information through a gossip protocol that makes use of a staggered broadcast mechanism. In this work, we show that the convergence delay in the network is larger than what would be expected from the protocol's specification and that payment attempt failures caused by the delay are more frequent, t...
Preprint
Payment channel networks, such as Bitcoin's Lightning Network, promise to improve the scalability of blockchain systems by processing the majority of transactions off-chain. Due to the design, the positioning of nodes in the network topology is a highly influential factor regarding the experienced performance, costs, and fee revenue of network part...
Preprint
The Lightning Network is a scaling solution for Bitcoin that promises to enable rapid and private payment processing. In Lightning, multi-hop payments are secured by utilizing Hashed Time-Locked Contracts (HTLCs) and encrypted on the network layer by an onion routing scheme to avoid information leakage to intermediate nodes. In this work, we howeve...
Article
As online sources are becoming more prevalent in journalism and scientific literature, the ephemeral nature of the World Wide Web is becoming an increasingly serious issue for their verifiability, replicability, and reproducibility. The architecture of Webchain, a new system enabling source and reference verifiability on the Web, is combining distr...
Conference Paper
In order to propagate transactions and blocks, today's blockchain systems rely on unstructured peer-to-peer overlay networks. In such networks, broadcast is known to be an inefficient operation in terms of message complexity and overhead. In addition to the impact on the system performance, inefficient or delayed block propagation may have severe c...
Preprint
Zcash is a privacy-preserving cryptocurrency that provides anonymous monetary transactions. While Zcash's anonymity is part of a rigorous scientific discussion, information on the underlying peer-to-peer network are missing. In this paper, we provide the first long-term measurement study of the Zcash network to capture key metrics such as the netwo...
Preprint
The Lightning Network is the most widely used payment channel network (PCN) to date, making it an attractive attack surface for adversaries. In this paper, we analyze the Lightning Network's PCN topology and investigate its resilience towards random failures and targeted attacks. In particular, we introduce the notions of channel exhaustion and nod...
Conference Paper
Payment channel networks use off-chain transactions to provide virtually arbitrary transaction rates. In this paper, we provide a new perspective on payment channels and consider them as a flow network. We propose an extended push-relabel algorithm to find payment flows in a payment channel network. Our algorithm enables a distributed and concurren...
Article
Payment channel networks use off-chain transactions to provide virtually arbitrary transaction rates. In this paper, we provide a new perspective on payment channels and consider them as a flow network. We propose an extended push-relabel algorithm to find payment flows in a payment channel network. Our algorithm enables a distributed and concurren...

Citations

... Currently the sender node mitigates this uncertainty by entering a trial-anderror loop for delivering payments. However, past experiments have demonstrated that payments are often failing, in particular when the amounts to be delivered are increasing [3,6,10,13]. ...
... We note that LN has multiple client implementations (LND, c-lightning and eclair) with variations in how they construct paths [39]. For our analysis we used LND's implementation, as majority of the nodes (> 90%) use LND [29,35]. The routing algorithms of the other implementations can be easily incorporated by just modifying the weight function, before calculating best paths using Dijkstra. ...
... Passive measurements are a common method for gaining an understanding of peer-to-peer networks [15,16]. The basic procedure of a passive measurement is the same for any P2P network. ...
... NIBs and GIB P2P networks are structured overlay networks that communicate through the Internet using the Kademlia protocol [25]. These networks also use the Kademlia protocol to implement the broadcast algorithm proposed in [26,27] for broadcasting transactions, blocks, and messages associated with the consensus process. This broadcast algorithm reduces message complexity by enabling validators to share broadcast responsibility. ...
... A greedy algorithm is designed to select the channels to be flooded in order to maximize the locked capacity. This is also similar to what is proposed in [18], where they analyze attack strategies by making use of the topological properties of the LN: for example they present some strategies to choose nodes to be removed for partitioning attacks. They propose strategies such as removing nodes by decreasing degree, by decreasing betweenness and eigenvector centrality, and by highest ranked minimum cuts. ...
... To establish a new connection, unconnected parties must constantly negotiate and agree over multiple aspects, thus, yielding high transaction costs and reducing performance and scalability. Against this backdrop, multiple users can build payment channel networks, which allow unconnected users to conduct transactions by routing payments over intermediaries [27]. These networks typically draw upon Hashed Timelock Contracts (HTLC), as a special class of smart contracts that is established between parties of a transaction and transferred to the blockchain for execution [28,29]. ...
... For this work we assume that the intended message path is fixed during the setup of the protocol -i.e. the initiating agent has selected the full path. We do not make any assumptions about the knowledge of the intermediate agents Though the path selection process often presents unique problems [19,33,36], we consider it out of scope of this work, as it is often domain-specific. 2 ...