Bitcoin Developer on 0xB10C's Blog

8 days ago

Earlier this week, I produced a Nix-built bitcoind binary for Bitcoin Core v31.0 whose hash exactly matches the official Guix-built x86_64-pc-linux-gnu release binary. The result came out of a three year old side project, with a difficult goal: Can a binary built with Nix be made bit-for-bit identic

Bitcoin Optech Newsletter #406 Recap Podcast

9 days ago

I joined Murch, Gustavo and Mike on the Bitcoin Optech Newsletter #406 Recap Podcast to talk about TCP holepunching and peer-observer P2P monitoring tools, which both were mentioned in the Optech Newsletter #406. Bitcoin Optech Newsletter #406 Recap Podcast

OpenSats Work-Log 9

a month ago

This is a copy of the 9th work-log I sent to OpenSats for my LTS grant. Disclaimer: Some information that is not (or not yet) meant to be published may have been redacted. What did you work on? In February, March, and April of 2026, I flew to Brazil to mentor upcoming Vinteum and B4OS devs as well

BIP-54: Block propagation and validation duration during slow-to-validate blocks on Signet

2 months ago

During last week’s demonstration of slow blocks on Signet, I ran a custom P2P client that connected to all ~190 listening Signet nodes on IPv4 and Tor. The goal was to measure block propagation speed through the network as well as block validation speed on a per node basis. Originally posted on bnoc

BIP-54 demo stream: Slow block validation on Signet

2 months ago

In April 2026, Antoine Poinsot and Anthony Towns publicly demonstrated a few slow-to-validate blocks on the Signet test network. These blocks are currently valid, but would be invalid under the BIP-54 Consensus Cleanup rules. I covered this event by streaming the behavior of a Bitcoin Core (affected

Panel: Exploiting Bitcoin

Discussion on the landscape of exploiting bitcoin with Matthew Vuk, Matthew Zipkin, Niklas Gögge, Sjors Provoost, and 0xB10C.

Hackathon Finalist: localprobe

Presented my hackathon project localprobe in the finals.

localprobe: detect Bitcoin nodes running on the same machine as your (Firefox) browser

You’re running a Bitcoin node on the same machine as your (Firefox) web browser? Yeah, I and everybody else can tell… localprobe is a small JavaScript snippet I built at the btc++ Floripa 2026 exploits hackathon, where it won 2nd place. It detects whether you are running a Bitcoin node on the same m

Recap: A network wide DoS bug in Bitcoin Core

I did a recap on the a network wide DoS bug and highlighted a metrics that we are monitoring now to catch similar bugs in the future. Slides (Google Slides)

Monitoring Workshop at Vinteum BDL 2026

I held a four hour long monitoring workshop for the current Vinteum Bitcoin Developer Launchpad cohort. I talked about my experience working on open-source Bitcoin projects over the last few years and I went over my Map of Bitcoin Monitoring I created as an overview for this workshop. Slides (Google

OpenSats Work-Log 8

4 months ago

This is a copy of the 8th work-log I sent to OpenSats for my LTS grant. Disclaimer: Some information that is not (or not yet) meant to be published may have been redacted. What did you work on? In November and December 2025, and January of 2026, I primarily focused on building out peer-observer too

OpenSats Report 8

4 months ago

This is a slighly edited copy of the 8th report I sent to OpenSats for my LTS grant. Note that I may have redacted some information that is not or not yet meant to be published. What did you work on? In November and December 2025, and January of 2026, I primarily focused on building out peer-observe

Bitcoin Network Monitoring with b10c: SLP707

6 months ago

In this episode, Stephan Livera and I discusses my work in the Bitcoin ecosystem, focusing on the importance of censorship resistance, the role of mining pools, and the implications of OFAC sanctions on Bitcoin transactions. I introduce my peer-observer project aimed at monitoring the Bitcoin P2P ne

Monitoring Bitcoin’s P2P network: Insights from the peer-observer Project

7 months ago

I presented about “Monitoring Bitcoin’s P2P network: Insights from the peer-observer Project” at the Chaincode Labs Bitcoin Research Day 2025. Slides (Google Docs)

OpenSats Work-Log 7

7 months ago

This is a copy of the 7th work-log I sent to OpenSats for my LTS grant. Disclaimer: Some information that is not (or not yet) meant to be published may have been redacted. How did you spend your time? Publications & Talks Continued my “Stats on compact block reconstructions”: thread by posting an u

Support from LocalhostResearch for peer-observer

8 months ago

Localhost Research supported my peer-observer project by sponsoring three servers for a demo instance, which can be found on demo.peer.observer. Compared to the public.peer.observer instance, this allows everyone to explore the metrics and data extracted from two Bitcoin Core nodes, while no informa

OpenSats Work-Log 6

10 months ago

This is a copy of the 6th work-log I sent to OpenSats for my LTS grant. Disclaimer: Some information that is not (or not yet) meant to be published may have been redacted. How did you spend your time? In May, June, and July of 2025 I finished mainnet-observer up and launched it, gave a talk on my p

peer-observer: A tool and infrastructure for monitoring the Bitcoin P2P network for attacks and anomalies

10 months ago

Over the past few years, I’ve been working on monitoring tools for the Bitcoin network. One of these projects is peer-observer: A tool and infrastructure for monitoring the Bitcoin P2P network for attacks and anomalies. This post describes the motivation for starting yet another Bitcoin network obse

Notes on 'DoS due to inv-to-send sets growing too large' from May 2023

In October 2024, the Bitcoin Core project disclosed a Denial-of-Service due to inv-to-send sets growing too large, which I authored, for Bitcoin Core versions before v25.0. I have a few notes and screenshots from my investigation back then that I want to persist here. In early May 2023, my monitorin

peer-observer: A tool and infrastructure for monitoring the Bitcoin P2P network for attacks and anomalies

I presented about my peer-observer project during the BTC Prague dev/hack/day 2025. Slides (Google Docs)

OpenSats Work-Log 5

This is a copy of the 5th work-log I sent to OpenSats for my LTS grant. Disclaimer: Some information that is not (or not yet) meant to be published may have been redacted. How did you spend your time? Publications & Talks Continued my “Stats on compact block reconstructions”: thread by posting an u

Bitcoin Mining Centralization in 2025

This post explores Bitcoin Mining Centralization in 2025 by looking at the hashrate share of the current five biggest mining pools. It presents a Mining Centralization Index and updates it with the assumed proxy pooling by AntPool & friends. It shows that Bitcoin mining is highly centralized today,

Invalid mining jobs by AntPool & friends during forks

Looking deeper into @boerst’s recent observation about invalid mining jobs by AntPool & friends to discuss his hypothesis about “selfish mining” and “glitchy template code”. I conclude that it’s probably a bug in AntPool’s coinbase creation code and agree with @boerst’s conclusion that this is anoth

OpenSats Work-Log 4

This is a copy of the 4th work-log I sent to OpenSats for my LTS grant. Disclaimer: Some information that is not (or not yet) meant to be published may have been redacted. What did you work on? Publications My mininpool-observer project detected 15 OFAC sanctioned transactions missing from blocks.

Fifteen OFAC-sanctioned transactions missing from blocks