Thread by @muneeb

“When everyone zigs, Stacks zags.”
— Nick Grossman, USV

The popular opinion in crypto is that proof-of-stake is the future. Stacks recycles Bitcoin’s PoW and avoids PoS.

Why do we prefer PoW? Tweet thread👇

1/ First of all, intelligent people I respect, e.g., Silvio Micali (Algorand), are working on proof-of-stake, so clearly, I think it’s a design space worth exploring.

Given that enough smart people are already exploring PoS, I’m more interested in researching other designs.

2/ I don’t like slashing conditions in PoS. An event like a network partition (however rare that might be) can slash funds of honest nodes.

That’s why in Stacks, we had a design requirement not to have any slashing conditions.

3/ In PoW, it’s hard for an attacker to produce many different blockchain histories (every history has energy cost).

I don’t like the attack surface where PoS chain histories are cheap to produce.

4/ Probabilistic finality typically used with PoW means that a blockchain can route around failures. Instant finality has benefits but also opens up potential halting scenarios.

Stacks follows probabilistic finality similar to Nakamoto consensus, i.e., deep reorgs are allowed.

5/ Independent verification is critical for blockchains. With PoW, anyone can run a node and independently decide on the correct fork, i.e., the fork with the most amount of energy spent. 

Trusted channels are needed for new PoS nodes to agree on the correct fork.

6/ PoS systems are actively researched and already scaling in production.

Alternatives to PoS are, however, under-explored; added reason for our recycling Bitcoin’s PoW work.

Avoiding herd mentality is beneficial for our industry. We’re not building yet another PoS system.

P.S: For energy consumption, this is green like PoS, but it’s not PoS.