A scalable, interoperable & secure network protocol for the next web
Polkadot is a network protocol that allows arbitrary data—not just tokens—to be transferred across blockchains.
This means Polkadot is a true multi-chain application environment where things like cross-chain registries and cross-chain computation are possible.
Polkadot can transfer this data across public, open, permissionless blockchains as well as private, permissioned blockchains.
This makes it possible to build applications that get permissioned data from a private blockchain and use it on a public blockchain. For instance, a school's private, permissioned academic records chain could send a proof to a degree-verification smart contract on a public chain.
Polkadot unites a network of heterogeneous blockchains called parachains and parathreads. These chains connect to and are secured by the Polkadot Relay Chain. They can also connect with external networks via bridges.
Connecting the dots
The heart of Polkadot, responsible for the network’s shared security, consensus and cross-chain interoperability.
Sovereign blockchains that can have their own tokens and optimize their functionality for specific use cases.
Similar to parachains but with a pay-as-you-go model. More economical for blockchains that don’t need continuous connectivity to the network.
Allow parachains and parathreads to connect and communicate with external networks like Ethereum and Bitcoin.
Secure the Relay Chain by selecting trustworty validators and staking dots.
Secure the relay chain by staking dots, validating proofs from collators and participating in consensus with other validators.
Maintain shards by collecting shard transactions from users and producing proofs for validator.
Monitor the network and report bad behavior to validators. Collators and any parachain full node can perform the fisherman role.
Elected to represent passive stakeholders in two primary governance roles: proposing referenda and vetoing dangerous or malicious referenda.
Composed of teams actively building Polkadot. Can propose emergency referenda, together with the council, for fast-tracked voting and implementation.
Polkadot’s relay chain is built with Substrate, a blockchain-building framework that is the distillation of Parity Technologies’ learnings building Ethereum, Bitcoin, and enterprise blockchains.
Polkadot’s state machine is compiled to WebAssembly (Wasm), a super performant virtual environment. Wasm is developed by major companies, including Google, Apple, Microsoft, and Mozilla, that have created a large ecosystem of support for the standard.
Polkadot’s networking uses libp2p, a flexible cross-platform network framework for peer-to-peer applications. Positioned to be the standard for future decentralized applications, libp2p handles the peer discovery and communication in the Polkadot ecosystem.
The Polkadot runtime environment is being coded in Rust, C++, and Golang, making Polkadot accessible to a wide range of developers.
Processing transactions in parallel
Parachains are specialized blockchains that connect to Polkadot. They will have characteristics specialized for their use cases and the ability to control their own governance.
Interactions on parachains are processed in parallel, enabling highly scalable systems.
Transactions can be spread out across the chains, allowing many more transactions to be processed in the same period of time.
Multi parallelized transactions
Polkadot is solving many of the problems that have held back blockchain technology so far — all in one place, without compromising.
In both Proof-of-Work and Proof-of-Stake systems, blockchains compete with each other over resources to secure their networks, and blockchains are easily attacked until they develop a significant community to support their network.
Polkadot takes a different approach by letting blockchains pool their security, which means that the blockchains' security is aggregated and applied to all.
By connecting to Polkadot, blockchain developers can secure their blockchain from day one.
Updates to the protocol happen fork-free via transparent on-chain voting, so protocol development never stalls due to the lack of a clear process. The relay chain uses a sophisticated governance mechanism that is designed to establish a transparent, accountable and binding process for resolving disputes and upgrading the network.
DOT tokens are used to participate in governance decisions, including tabling proposals, voting, and bonding.
Parachains are free to design their own governance mechanisms, allowing for maximum freedom without affecting other parachains.Learn more about Polkadot’s governance
Polkadot uses its original GRANDPA (GHOST-based Recursive Ancestor Deriving Prefix Agreement) consensus for a more secure and resilient network.
Under good network conditions, GRANDPA can finalize blocks nearly instantly. Under bad network conditions, like a network partition, GRANDPA can finalize large quantities of blocks (theoretically millions) at once when the partitions resolve.Learn more about GRANDPA.
Polkadot is rolling out the most robust platform for security, scalability and innovation. Having launched the genesis block of its Relay Chain in May 2020, Polkadot is now on track to launch several parachains in 2021.See Launch Roadmap
What are teams building on Polkadot? Just a few examples:
Oracle chains that make off-chain data available to all contracts on the Polkadot network (ChainLink)
Identity chains that link accounts to a persistent identity and enable access to other parachains through fewer accounts (Speckle OS)
Internet of Things chains that set IoT standards for machine-to-machine communication (MXC Protocol)
Zero Knowledge privacy chains, or bridges to existing ZK-snarks chains (e.g. Zerochain)
File storage chains that incentivize storing data on-chain
Bridge to Ethereum, allowing Ethereum smart contracts to interact with the Polkadot network