In December 2020, ETH2.0 Beacon Chain launched. This Phase 0 launched forms part of a multi-year process that will see ETH1.x transform from a PoW (Proof of Work) to a PoS (Proof of Stake) blockchain.
This is an exciting period in Ethland and is the product of years of research of optimal solutions to ensure Ethereum remains secure and decentralized despite a change of consensus mechanism. its been a long held belief that PoW has the most security guarantees unlike, say, PoS.
I have previously covered some forms of attacks against Proof of Stake chains and so, with Ethereum moving to PoS, let’s see how it intends to defend against these PoS attacks or if any are applicable at all!
Eth2.0’s security model is making attacks extremely expensive by putting up economic value-at-loss i.e. security relies of penalties, not rewards.
Eth2.0:
We have indeed already seen a validator get slashed ~0.25 ETH:
Eth2.0 Beacon Chain uses weak subjectivity checkpoints, which is a similar concept to “genesis block”, in that it’s a block that is agreed upon by the entire network as the “real” chain.
The Eth2.0 research work went a step further to determine a weak subjectivity period - which is defined as the number of recent epochs within which there must be a weak subjectivity checkpoint so that an attacker who takes control of the validator set at the beginning of the period is slashed at least a threshold amount in case a conflicting finalized checkpoint is produced.
The Ethereum re-engineering from PoW to PoS has been defined as "trying to change an airplane engine mid-flight”. It could be disastrous if it all goes wrong, but so far, all the research work and planning that went into this is moving along nicely.
I will be eagerly watching, and researching, this progress over the next 12-18 months!