Coin columns · Mainnet Province
Polkadot: A ‘Chain of Chains’ Under One Security Umbrella
Gavin Wood’s multichain network and what DOT is used for
Polkadot is a network in which separate blockchains connect to one central chain, sharing its security and exchanging messages. Its own coin, DOT, secures the network and is used to vote on its direction.
1. Who built it
Polkadot was set out in a 2016 white paper by Gavin Wood, an Ethereum co-founder who wrote Ethereum’s technical specification (the Yellow Paper). The Swiss Web3 Foundation funds research, while Parity Technologies, founded by Wood, has built the core software. After the 2017 token sale, a bug in Parity’s wallet code froze much of the ether raised.
Kusama, a faster-moving ‘canary network’ where new features are tested first, launched in 2019. Polkadot itself started in May 2020, and DOT became transferable that August. On the Crypto Nation map, DOT is the city-hall tower at the centre of the Polkadot neighbourhood in the Mainnet Province, because it is that chain’s own coin.
2. Relay chain and parachains
At Polkadot’s centre is the relay chain, and around it connect ‘parachains’, blockchains built for particular purposes. Parachains produce their own blocks, but the relay chain’s validators make the final checks, so small chains can borrow the security of the larger network. Chains exchange assets and data through a common message format, XCM.
Security comes from nominated proof of stake (NPoS): validators lock up DOT, and ordinary holders nominate trustworthy validators, sharing their collateral and rewards; if a validator misbehaves, its nominators’ stake can be cut too. Through on-chain voting called OpenGov, DOT holders decide upgrades and even how the shared treasury spends its funds.
3. Milestones
From late 2021, parachain slots were handed out by auction, bringing in chains such as Acala, Moonbeam and Astar. In 2024 ‘agile coretime’ replaced auctions with renting blockspace (coretime) as needed, so small projects pay only for what they use, alongside speed upgrades such as asynchronous backing and elastic scaling.
In 2024 Gavin Wood unveiled JAM, a next-generation design to succeed the relay chain. In 2025 balances, staking and governance began moving from the relay chain to Polkadot Hub, which is also gaining Ethereum-style smart contracts, and in September a community vote capped total DOT supply at 2.1 billion, with new issuance to fall in steps.
4. Things to know
Polkadot’s sophisticated design has often been called hard for developers and users to grasp, and criticism that parachain auctions were costly and slow led to repeated redesigns. Some also note that user activity has lagged Ethereum L2s and other fast chains.
On-chain governance is open to everyone, but turnout can be low and large holders can carry weight; treasury spending on marketing, for example, sparked debate about value for money. Before the cap, DOT also had relatively high yearly issuance.
Written from information public up to October 2026. It does not recommend or rate any coin and is not investment advice. If something is wrong, please tell us through the contact page.