Substrate Technology


Developers are often forced to make tradeoffs between compatibility, security, and efficiency to interact with data that exists off-chain and cross-chain. This has led to the creation of bridges, oracles, and other interoperability protocols, all with their own limitations.

Substrate takes a unique, multifaceted approach to address these tradeoffs.


Substrate-based blockchain networks have the choice of either operating as a solo chain, a solo chain with a bridge, or to integrate as a parachain. Integrating as a parachain enables independent Substrate-based blockchains to gain interoperability with the other independent blockchains. The secret sauce of parachain interoperability lies in XCMP (Cross-Chain Message Passing). XCMP enables parachains to share trusted logic, for example, transferring tokens between networks, without any additional trust assumptions!

Blockchain networks that are not parachains, such as Ethereum, are accessible through parachain bridges. By becoming a parachain on networks such as Polkadot or Kusama, your Substrate-based blockchain also gains interoperability with major blockchains such as Bitcoin and Ethereum while gaining pooled security.

Learn more about Cross-Chain Message Passing (XCMP) across parachains »


Integrating with Polkadot has advantages beyond gaining bridge access to other networks, most significantly in terms of security. Legacy blockchains are solely responsible for the security of their own network. This is generally limited by the size of the network: the smaller the network the more susceptible it is to a successful attack.

Integrating with Polkadot or other blockchain networks is of course optional. Enterprises often choose to begin with a standalone network with the option of connecting to other networks as they evolve.

Learn more about shared security using Polkadot »

See Astar's case study on enabling dapps to co-exist across blockchain networks.

Case Study


Off-Chain Worker (OCW)

For computationally intensive and even non-deterministic expensive tasks


Off-Chain Storage

Enables data to be stored and accessed by both off-chain workers and on-chain logic without requiring consensus over the whole network


Off-Chain Indexing

Stores a small amount of information on chain, such as a hash, that can be used to look up and verify data stored off-chain independently of OCWs


Compute and storage come at a cost in any system, even more so with blockchain networks since many nodes perform the same computation and store many copies of the data. Often the concept of "gas" is introduced because of computational resource limitations. Because of Substrate’s modularity, gas is completely optional, and the introduction of off-chain features greatly reduces computation and storage costs.

Off-chain features run in their own execution environment outside of the Substrate runtime. This creates a separation of concerns and ensures block production is not impacted by long-running off-chain tasks.

With Substrate you're not only free to choose your parameters such gas costs, governance, and consensus, you're also free to choose how your blockchain is deployed and if/how it should communicate with other networks. This means your chain can operate completely independently or connect to networks such as Polkadot to gain greater security and interoperability.

Read more about off-chain features in the in the in the documentation »

Substrate is the antithesis of blockchain network maximalism, offering interoperability without forgoing compatibility, security, or efficiency.