Part 7/17:
He highlights that PoS is fundamentally different: validators are chosen deterministically based on their stake, and attacks become much easier to execute once an actor controls more than 50% of stake (the "51% attack"). Unlike proof of work, where costly energy makes attacks prohibitively expensive, in PoS, the costless construction of alternative chains raises concerns of long-range attacks and nothing-at-stake problems.
Strengths and Weaknesses of PoS
Advantages:
Lower energy costs, making it more sustainable.
Facilitation of sharding, increasing throughput.
Potential for self-healing mechanisms that revert after attacks or forks.
Permissionless participation, as long as you hold ETH.
Risks: