Ethereum is changing. It will migrate from Proof of Work to Proof of Stake, and the some pillars of its architecture are changing as well. To understand this changes, we need to focus on the first of its upgrades: the Beacon Chain.
The Beacon chain will work with Proof of Stake Consensus and the validators will be responsible for creating and proposing new blocks to this chain. The validators that proposes a new block will be named PROPOSERS, and the validators who confirms the proposal will be named ATTESTOR. Only validators that are marked as "active" can propose and attest to blocks to be included in the Beacon Chain. In their design, there's a minimum number of attestors necessary to for a committee, and together they can validate a block proposal.
The Beacon chain will have some important functions:
- Store and maintain the registry of nodes that will act as validators
- Overseeing validator committees which regularly vote on proposed blocks.
- Enforcing network rules using penalties and rewards.
- Act as a central anchor point for shards to report to regularly. The intention is to facilitate quick cross-shard transaction execution.
As of the time of this writing, each node will have to stake 32 ETH to participate in this Proof of Stake system (around $5,555). Unlike PoW, there is no block mining competition and so block proposers are chosen at random by the beacon chain to carry our hashing. By staking a significant amount of ETH, the validators are on risk of losing all its ETH if they misbehave. Blocks will be produced at 16 second intervals and a randomly chosen block proposer receives all information from Beacon chain validator and organizes them into a block that will be published in the Beacon Chain. The idea is a super fast, super secure chain that will work with admin features over the sharded network.
The supervisory role of the Beacon chain will be key to manage the PoS network. Good behavior will be rewarded and bad behavior will be penalised. Validators are expected to vote. In case they participate in the committee and don't vote, they will also lose its stake. In case the amount of ETH falls below 16 ETH they will be ejected from the validator set.
In Ethereum's architecture, each shard will be connected to the Beacon chain via a central spine. Every now and then a photograph of their state will be taken and their current state will be recorded in the Beacon Chain block. When the beacon chain block is completed each shard will also be considered "final" and cross-shard transactions will be able to happen. Processing this cross-shard is one of the key features of the Beacon Chain as explained above. And they all need to wait for this final confirmation from the Beacon chain block to be processed.
Because all the block finality is subject to the speed and final approval of "mothership" Beacon Chain, it will act as an important bottleneck in the system. Like every distributed network, the speed where transactions are validated, they will be subject to the slowest node in the network. The Ethereum network is deploying a lot of computational power and resources for validators to join the Beacon Chain.
As explained in a previous post (see http://www.itsencrypted.com/blog-1/web-30/sharding-1 ) , the idea is that the computational power to process all the transactions of the network is divided into sharded chains.