Signal adds a payments feature with a privacy-focused cryptocurrency

What's the consensus function you use on the mobile coin blockchain. Couldn't see if it's proof of work or proof of stake.

We use a modified version of the Stellar Consensus Protocol that we reimplemented from scratch using Rust.

https://github.com/UkoeHB/Mechanics-of-MobileCoin/blob/maste... << Page 81 is where you want to go.

So this does seem to use some voting mechanism instead of scarcity through PoW.

How do you prevent the sybil attack then if there is no scarcity?

I.e. what prevents an individual from spinning up 10 million nodes to get more voting power?

Stellar is essentially a liquid democracy system similar to DNS. The core proof at the heart of David Mazieres paper is that in a densely interwoven graph, any set of nodes in a quorum slice reaching consensus is graph consensus. Regarding Sybil, nodes define their own trust relationships, so membership is open but not automatic.