Comment by brianolson

(my day job is developer on Proof-of-Stake Algorand block chain, I'm a developer, this may not be polished official PR) Article's theory about malicious old blocks doesn't hold up. Let's say I start a new node and verify history since the beginning. Somewhere along the line I'm connected to a malicious node which hands me a fictionalized block. It would need to have been signed by not just one but about 30-45 accounts _which had stake at that time_. Proof-of-Stake attacks aren't about having 51% of the CPU that overwhelms a Proof-of-Work system, but about having 60-70% of the _value_ in the network. So, if Warren Buffet comes along and wants to spam our network, I guess he could, but that would destroy the network and destroy his value that he sunk into the network. _That_ is a guardrail for PoS systems as much as any crypto or consensus-protocol element (and the algorithms are right, original article misunderstands them).