>Author: Filippo Franchini, Web3 Foundation, compiled: OneBlock+

Polkadot is an innovative multi -chain blockchain platform,It aims to achieve interoperability and sharing safety between different blockchain.This article will be explored in detailPolkadot’s security mechanism,Pay special attention to how its core (Core) and the ON-Chain system provides shared security for Rollups,And how to ensure the availability and effectiveness of the entire network.

Polkadot’s security architecture

Polkadot’s security mechanism depends on itUnique core and validators.Polkadot’s parallel chain (Parachains) connects to the Relay Chain through the core, andEach core consists of 5 verifications (dots)The group guardian, these groups rotate between the cores every minute,And change members every 4 hours.

The first -level chain (L1) sends a block candidate with some proof to the core.In the core3/5 verificationAfter receiving and verifying the data, the candidate for L1 block isBack up to the Polkadot relay chain.(Figure: Orange, R1)

Since then,The core is occupied(In the picture: red),The backup will distribute some tactical codes(Used to reconstruct information for further inspection and processing disputes) and block candidate recovery (CR, recorded in the relay chain)Given the verification person outside the core.

Polkadot’s BABE (block production algorithm) will choose a block author,Acquire the block candidate in the subsequent relay chain block (in the figure: blue, R2), and the core becomes available.Used to receive follow -up candidate information for backup.

In the Polkadot 1.0 version without asynchronous support,L1 block is included in the relay chain every 12 seconds, and the core verification person executes 0.5 seconds.

In Polkadot 1.0,A L1 chain can occupy a core of up to 2 years.

Overview of parallel chain protocol

Original: https://wiki.polkadot.network/docs/learn-parachains-protocol

The parallel chain protocol passes a process that can be repeatedly carried out in parallel, and a parallel chain block is created from creation to the relay chain.The protocol allows the network to make efficient slices while maintaining a strong security guarantee.Availability and Validity (ANV) protocol describes from the perspective of availability and effectivenessParallel chainprotocol.

Main role

Validators (Validators): Responsible for verifying the validity proof of the parallel chain block (POV),Make sure the availability of POV in the specified period of time.The verification person has a deposit on the chain,It may be confiscated partly or all when the behavior is not end.

Collators (Collators): Create a POV for verification inspection.To create a POV, you need to be familiar with the trading format and block creation rules of specific Parachain.And have a complete state access right.

The main stage of parallel chain protocol

Inclusion pipline: The collector sends the parallel chain block (Parablocks) together with POV to the verification.Verifier checks whether Parablocks follows the status conversion rules and signed the results.After getting enough positive results, the block is backup and incorporates into the relay chain, but it still needs to be approved.

Approval process (APPROVAL Process): Examples are checked for additional inspections,If you pass, the parallel chain block will be approved.

Data usability and effectiveness protocol (ANV)

The ANV protocol reviews the parallel chain protocol from another angle,It is emphasized that Parablock must be available and effective before incorporating the final relay chain.Divided into five stages:

• Three stages in the process: Parallel chain phase, relay chain submission stage, availability and unavailable phase.

• Two stages in the approval process:Task allocation and secondary (effective) inspection and chain selection.

Polkadot provides a strong security mechanism through its core and verification system, as well as the parallel chain protocol.Ensure the efficient operation of the network and the effective verification of the block.With the development of technology and the continuous optimization of protocols,Polkadot is expected to continue to play an important role in the field of blockchain interoperability and sharing security.