biptreexo: draft BIPs for utreexo \ stacker news ~bitcoin

Utreexo is a different way for nodes to keep track of which coins are spendable. Instead of generating a UTXO set from the history of all the blocks, utreexo introduces an accumulator that allow lightweight nodes to only keep track of small proofs for the coins they care about.

However, I think this also means that such light nodes could only interact with other nodes that speak utreexo, and wouldn't be able to have normal bitcoin nodes as peers (honestly, I'm not fully sure about this).

It seems to me that this creates a separate network -- in the same way that tor is a separate network from clearnet -- and I wonder what risks this might introduce into Bitcoin. Currently, if we don't have a healthy number of nodes that have both clearnet and tor peers, it is possible for an attacker to try to isolate the two networks from each other. Does the utreexo scheme create a similar concern?

Utreexo's design is driven by the need for Bridge Nodes: nodes that maintain backward compatibility with existing Bitcoin nodes and wallets that do not use Utreexo. A bridge node must be able to generate an inclusion proof for any UTXO at any time, with low latency, to support lightweight clients and peer nodes.

I did a bit of digging and couldn't find a really killer explanation of utreexo anywhere. This recent Bitcoin OpTech podcast had one of the BIP authors on to talk about a utreexo project called Floresta and was probably the best explanation I've heard so far.

As far as the draft uxtreexo BIPs, there are three BIP drafts in the linked repo:

- Accumulator - P2P - Validation

If you want to learn more about utreexo, check out the Bitcoin OpTech page for it, BitMex's blog, or the original paper

102 sats \ 3 replies \ @d680ecaa8e 4 Aug

Not in every case light nodes could interact with other nodes please review the documentation.

0 sats \ 2 replies \ @Scoresby OP 4 Aug

So utreexo light nodes could receive blocks from regular bitcoin nodes and use that information to learn about newly created outputs?

102 sats \ 1 reply \ @d680ecaa8e 5 Aug

this is what i mean exactly

0 sats \ 0 replies \ @Scoresby OP 5 Aug

Thanks for the correction. I will spend more time looking at their documentation.

223 sats \ 0 replies \ @claos545 4 Aug

Utreexo compresses the UTXO set into a compact accumulator. That means you don't need to store the entire UTXO set locally, just a root and some proofs. For someone trying to run a full Bitcoin node off modest hardware and poor connectivity, this is huge.

I've been testing lightweight setups for LN self-custody using LNbits + Phoenixd + Electrum servers. One major bottleneck is syncing and maintaining full nodes, especially when you don't have steady internet or storage.

With Utreexo, a fully validating node becomes realistic, even on old laptops or mobile rigs. Combine that with a mesh network or even some USB sneaker-netting and you could have resilient Bitcoin infra running off-grid.