For the past few months, I’ve been working with Clara Shikhelman at Chaincode Labs on the issue of jamming attacks in the Lightning Network.| s-tikhomirov.github.io
Lightning is currently source-routed. This means that each sender does a local route search on the full network graph. This may become unsustainable as Lightning grows grows. Naively outsourcing route discovery to dedicated servers harms privacy: the servers know who is paying whom. The LightPIR paper proposes a solution. The authors combine private information retrieval with all-pairs-shortest-path pre-computation with hub labeling, optimized for real LN topology. In this post, I summarize t...| s-tikhomirov.github.io
In this post, we summarize our paper on channel balance probing in the Lightning network. It supersedes our earlier work on this topic. A video presentation based on this post (a longer version is also available): First, we briefly introduce the Lightning network (LN) and the channel balance probing attack. Then, we propose an enhanced probing technique that allows an attacker to extract more private information faster. We run simulations based on real-world data and conclude that the propose...| s-tikhomirov.github.io
For the significant portion of 2018, as part of my PhD studies in CryptoLUX group at the University of Luxembourg, I’ve been working on network-level privacy attack on Bitcoin and other cryptocurrencies with professor Alex Biryukov. This blog post summarizes our findings, which have been published in 2019 (“Deanonymization and linkability of cryptocurrency transactions based on network analysis”). You can watch my presentation at EuroS&P 2019 in Stockholm (press CC for subtitles; slides...| s-tikhomirov.github.io
This August, Berlin was the global center of all things decentralized. Thousands of blockchain enthusiasts gathered for the Berlin Blockchain Week – a series of conferences, meetups, and a hackathon. In this post, I’ll share my thoughts on Web3, which was the primary topic of the the first major event of the week – Web3 Summit. [1] For Russian speakers: you can watch and listen to our coverage of Berlin Blockchain Week in Basic Block podcast. I also participated in the ETHBerlin Zwei ha...| s-tikhomirov.github.io
Continuing the journey through layer-two technologies, here is a summary of the paper “eltoo: A Simple Layer2 Protocol for Bitcoin” by Christian Decker et al (see also: a summary in the Blockstream blog). Eltoo proposes a new construction for payment channels.[1] It is not a fully-fledged protocol, rather, it only describes one crucial building block – state revocation mechanism. As you might remember from my summary of “SoK: Off the chain transactions”, the crucial challenge in L2 ...| s-tikhomirov.github.io
Here is papers I’ve been waiting for for quite a while. Thinking about it, I’d be happy to have (co-)written it, had I directed my research into this topic a bit earlier. Today’s summary is based on a systematization of knowledge (SoK) paper by Lewis Gudgeon et al entitled “SoK: Off the chain transactions”. The readers of this blog must be familiar with some of the challenges in layer-two protocols which I outlined in previous paper summaries. But as in any rapidly developing field,...| s-tikhomirov.github.io
Let’s continue our journey though recent paper which suggest ways to optimize routing in payment channel networks. In previous posts, we looked an SilentWhispers and SpeedyMurmurs. Both approaches emphasized privacy as an important goal, but employed different constructions: landmark-based routing (SW) and embedding-based routing (SM). Today let’s look into a paper entitled “Routing cryptocurrency with the Spider network” (2018) by Sivaraman et al.| s-tikhomirov.github.io
In a previous post, I discussed SilentWhispers – a routing algorithm for credit networks. Today I’ll dive into a follow-up paper by a partially intersecting group of authors, entitled “Settling payments fast and private: decentralized routing for path-based transactions”, which presents a routing algorithm called SpeedyMurmurs.| s-tikhomirov.github.io