Phase 0 of Ethereum 2.0 is scheduled for activation at a tentative time in 2020. Upon activation, the update will enhance the security of Eth 1.0 due to the Finality Gadget feature.

It is the view of Alex Stokes, an analyst, that Finality Gadget will largely buffer the network against external attacks making it economically hard for etched ETH transactions to be reversed in a majority attack. During Eth 2.0, a transaction will only be reversed if a third of proven staked ETH is burned.

“ETH 2.0 phase 0 – coming in 2020 – will enhance the security of the ETH 1 chain drastically. With the Finality Gadget, the reversion of blocks will become extremely expensive, making Ethereum much more secure against attacks.”

In 18 months…

— David L💫 (@Deathkonen) January 12, 2020

Forecasts from various analysts place Phase 0 implementation in the second half of 2020. However, no one is sure as it the nature of development in open source platforms. Phase 0 of Ethereum 2.0 will entail the activation of the Beacon Chain.

1) 🎉Happy new year friends! We are announcing the latest release of Prysm @prylabs to support v0.9.3 beacon chain spec changes. The new release supports full mainnet config with deposit requirement set at 1/10th (3.2ETH)

— tchain.eth (@terencechain) January 7, 2020

The Beacon Chain is the main “system chain” of Serenity’s sharded blockchain. In simple terms, the Beacon Chain will coordinate hundreds of other Ethereum blockchains called shards as envisioned in the final workable version of Ethereum 2.0.

Then, Ethereum would have shifted from the Proof of Work–that is currently in use, to a Proof of Stake consensus algorithm where miners would be replaced by validators where Casper will resolve initial problems faced by early PoS systems of “nothing to stake”. However, the first implementation of Casper will leverage Proof of Work to verify and add new blocks to the new blockchain.

The Finality Gadget will factor in the consensus of Phase 0 of Ethereum 2.0 to further enhance the security of the original, Ethereum 1.0 chain.

In this way, the Ethereum community can derive value right from the first day of the activation of the Beacon Chain with improved security during transition:

“If we can feed Ethereum 1.0 block data into Casper’s “finality engine”, then we can utilize the enhanced security of the proof-of-stake protocol on the existing proof-of-work network.”