Currently, a block chain network and its expansion to the next massive growth system for topical application there is a contradiction, leading to increased competition for resources system, which has been reflected in the current EOS network resources (RAM and CPU) in congestion. Not only is the EOS, including square Ethernet, token bit block chain other networks this problem.
Polkadot proposed solution, which is a scalable heterogeneous multi-chain systems, the goal is to achieve interoperability formed isolated from each other network interworking block chain. Polkadot highly scalable, avoid hard bifurcation, can continue to upgrade.
Substrate-based architecture constructed IPSE parallel chains (parachain), Polkadot system architecture using main key structural bridge adapter (Bridge) cross-link communication. To ensure that the state of the relay parallel chains and chain IPSE Polkadot system consistency by mixing consensus mechanism, respectively BABE and GRANDPA.
BABE consensus algorithm
BABE (Blind Assignment for Blockchain Extension, " block chain extension blind assignment) is to verify that person and decide who is to generate a node generating a block algorithm .BABE mechanism between the new block in a mortgage and use Polkadot randomness cycle production distribution block slot to verify people.
Polkadot people will be involved in the verification of each lottery to decide whether they are producing block candidate for the slot. Time slot as a unit with a length of 6 seconds. Due to the randomness of this mechanism, multiple verification might be candidates for the same time slot. In the remaining time slots may be empty time lead to inconsistent blocks.
A plurality of certifier same time slot: When a plurality of people at the same time slot verification of the block production has also become candidates, and all blocks will have to broadcast network. However, this situation would be a game. Which specific certifier to win, depending on the network topology and delayed until finalized and cut forked so far.
There is no slot certifier: When there are no validation low enough qualified people to achieve production blocks in the random lottery, the slot will not block produced. However, the algorithm will choose to avoid this, keep the people always generate a verification block.
BABE need to fit and Grandpa, the blocks responsible for BABE, GRANDPA primarily responsible for achieving agreement between the block chain (e.g., parallel to the chain) to ensure the consistency of the final block.
Note: BABE should be noted that the algorithm is still perfect, the current Web3 Foundation Handan Kilinc Alper has released the latest BABE presentation document, the working mechanism explained in detail.
https://research.web3.foundation/en/latest/polkadot/BABE/Babe/