This is detailed on https://delvingbitcoin.org/t/great-consensus-cleanup-revival/710#p-1996-worst-case-block-validation-time-5

The worst block i could come up with takes around 3 minutes to validate with all 16 cores of my modern laptop’s CPU and a hour and a half of a RPi4.

Context: https://delvingbitcoin.org/t/consensus-cleanup-demo-of-slow-blocks-on-signet/2367/

First run: #1467394

my host has access to 8 shared AMD EPYC-Rome (2019) cores, not the newest and fastest, but should be plenty to validate a signet block...

I got some timestamps for a miner mining at Foundry's pool:

https://bnoc.xyz/t/two-block-reorg-at-height-941880/97/20

It indeed seems to be the case that they mined these two blocks just after the competing ones.

Ah, you were 47s faster!

localprobelocalprobe

Team:Team:

• b10c – https://github.com/0xb10c

What We Built:What We Built:

If your browser (Firefox does; Chrome/Brave/Edge are ok) leaks that are running a Bitcoin node (mainnet/testnets) on the same machine as your browser, localprobe alerts you about it by showing a privacy alert when you visit a website. Currently, https://b10c.me does (test by running bitcoind -regtest and visiting https://b10c.me). This leak might be used by e.g. advertisers to show you Bitcoin related ads.

Stack:Stack:

plain JS

Submission:Submission:

https://loot.fund/hackathons/bitcoin-exploits-edition/applications/13

Repo:Repo:

https://gist.github.com/0xB10C/4e6b3d8394bb375323e887945091ead5

Next Steps:Next Steps:

Using the same technique, we can actually harm remote Bitcoin nodes by DDoSing them from the browser. I've been working on a demo of this.

@btcpp maybe show this or I can briefly talk about this when the hackathon starts?

I have a few peer-observer / monitoring project ideas for the upcoming hackathon. With peer-observer, we have a real-time feed of Bitcoin Core events. A event is for example a P2P message arriving, a connection bening opened, us periodically fetching an RPC, ...

I run a tool that transforms events from this feed into a websocket with JSON messages for them to be used in the browser. Then, I have a few HTML pages that act as tools consuiming and displaying some of the events. See https://demo.peer.observer/websocket/

For the hackathon, you can use one (or even two) websockets of wss://demo.peer.observer/websocket/hal/ or wss://demo.peer.observer/websocket/len/ for building a nice demo or Proof of Concept of a browser visualization.

A few ideas are (but feel free to be creative and experiment!):

1. Build a real time Bitcoin Core debug log viewer: On the wss://demo.peer.observer/websocket/hal/ websocket (not on len) we are sending Bitcoin Core debug logs as JSON messages. Displaying this in the browser in real-time could be cool. Addtionally, filtering (i.e. grep) or highligthing certain messages would be cool. I think building this should be fairly simple.
2. A Bitcoin Core orphanage visualization: Bitcoin Core keeps something called an oprhange for transactions we don't know a parent for. There's a bit more information on it in https://github.com/bitcoin-core/bitcoin-devwiki/wiki/%5BP2P%5D-known-TxOrphanage-problems with a few links and context. Having a visualization of the orphanage in real-time in the browser would be nice. peer-observer fetches the getorphantxn RPC every 10s and sends it as JSON message via websocket. I've started working on a PoC in the past, but the orphanage has changed a bit since then: https://github.com/bitcoin/bitcoin/pull/30793#issuecomment-2379684081 - so you probably need to adapt this a bit. This is a bit harder than 1., since you need to learn about Bitcoin Core internals.

3. Be creative and explore the websockets and come of with something new and cool!

If you need help, feel free to come up to me and ask for help!

Also, have a look at the existing tools and their source code:

• https://github.com/peer-observer/peer-observer/tree/master/tools/websocket/www
• https://demo.peer.observer/websocket/

I'm giving a talk about a bug from 2023 in Bitcoin Core that had a noticable effect on the whole network at 11:15am.

You can find my slides on https://b10c.me/talks/028-btc++exploits/ and a blog post about the bug on https://b10c.me/observations/15-inv-to-send-queue/. The Bitcoin Core disclosure is on https://bitcoincore.org/en/2024/10/08/disclose-large-inv-to-send/.

you mean something like https://fork.observer?

Linking another post from 2023 where I2P had problems. This time it seems to be something else: #172367

It's perfect for this. You know exactly what's running on the hosts and you can scale it up easily by running the same (or similar) configuration on a different host.

See https://github.com/0xb10c/peer-observer-infra-demo and https://github.com/0xb10c/peer-observer-infra-library

Just saw this now. Feel free to ping me (you'll find contact info on b10c.me) if you're still interested @spiderman

I agree and have thought about this myself. I started packaging fork-observer for Umbrel, but couldn't really test it without an Umbrel node myself. Ideally, that's something someone else could do that a) has an Umbrel / Start9 node setup and b) has the time to do it.