Polkadot: The Complete Guide to Blockchain Bridges
The open-source Polkadot blockchain network enables several isolated, siloed blockchains to link and develop into “parachains,” which are application-specific sub-chains. The Substrate modular structure used by each chain produced with Polkadot enables developers to choose particular components that best suit their application-specific chain.
The “Relay Chain” serves as the common hub for all parachains, collectively known as the Polkadot network. The Relay Chain contains Polkadot’s consensus, finality, and voting logic but does not support application functionality; instead, it secures the network’s parachains. Better scalability, upgradeability, transparent governance, and cross-chain composability are goals of the network. The native token (DOT) is employed to coordinate and incentivise conduct among the various actors in its ecosystem and to advance the success and growth of the entire enterprise.
Technology behind Polkadot
The “Cross-Consensus Message Format” was created by Polkadot as a universal format for communication across parachains, different smart contracts, bridges, and Substrate pallets (XCM). The relay chain and parachains can exchange messages thanks to XCM and Vertical Message Passing (VMP). And Cross-Chain Message Passing (XCMP) enables parachains on the same relay chain to communicate with one another. A program that runs on the Cross-Consensus Virtual Machine is a message in XCM (XCVM). Using this network programming, other heterogeneous blockchain networks can create comprehensible cross-chain applications.
The parachains are able to communicate securely and natively because to the Cross-Consensus Messaging format (XCM). The natively validated full nodes of the Ethereum mainnet and their particular parachain, which conveys the state transition, are the same validators that sign the XCMP messages that secure the chains exchanging messages. In addition this architecture ensures unified finality and allows parachains to exchange any type of data between them safely.
Random data passing is made possible. This is due to the Relay Chain’s inherited security dynamic. There are currently fourteen active parachains. Each with an own area of expertise, such as DeFi, EVM smart contracts, social media, privacy, and games. Bridges to other projects, including Bitcoin and Ethereum, are in development.
The XCM method:
- Execution of a smart contract on Parachain A. Which involves sending a message.
- Parachain B’s collators continuously search for incoming messages
- On Parachain B, a Collator proposes a new block.
- Validators attest to their ability to read both inbound and outbound messages on both Parachains and come to an agreement.
Trust and Security Assumptions
Polkadot uses inherited hierarchical security, where the parachains are part of the central relay chain. The parachains’ collator nodes gather transactions and generate state transition proofs for the relay chain to validate, and the relay chain has validators.
The Polkadot system’s ability to proactively choose which parachains to interface with adds an additional layer of protection. One parachain has the ability to specify which particular parachains it wants to establish contact with. Additionally, it has the ability to choose the circumstances for receiving and handling incoming messages.
