--- category: Polkadot Protocol description: Protocol internals covering consensus, coretime, block production, cryptography, and chain architecture. page_count: 33 token_estimate: 5145 updated: '2026-06-25T12:38:13.291384+00:00' --- ## Agile Coretime https://docs.polkadot.com/reference/polkadot-hub/consensus-and-security/agile-coretime.md Explore the efficient scheduling mechanisms to access Polkadot cores to produce blockspace continuously or on-demand. ### Sections - Introduction `#introduction` - Bulk Coretime `#bulk-coretime` - Coretime Interlacing `#coretime-interlacing` - Coretime Splitting `#coretime-splitting` - On-Demand Coretime `#on-demand-coretime` --- ## Asynchronous Backing https://docs.polkadot.com/reference/parachains/consensus/async-backing.md Understand how asynchronous backing pipelines parachain block production, the protocol changes it introduces on the Relay Chain, and how parachains participate safely and efficiently. ### Sections - Introduction `#introduction` - Configurations `#configurations` - Synchronous VS. Asynchronous Processing `#synchronous-vs-asynchronous-processing` --- ## Blocks https://docs.polkadot.com/reference/parachains/blocks-transactions-fees/blocks.md Understand how blocks are produced, validated, and imported in Polkadot SDK-based blockchains, covering initialization, finalization, and authoring processes. ### Sections - Introduction `#introduction` - What is a Block? `#what-is-a-block` - Block Production `#block-production` - Initialize Block `#initialize-block` - Finalize Block `#finalize-block` - Block Authoring and Import `#block-authoring-and-import` - Block Import Queue `#block-import-queue` - Additional Resources `#additional-resources` --- ## Bridge Hub https://docs.polkadot.com/reference/polkadot-hub/bridging.md Learn about the Bridge Hub system parachain, a parachain that facilitates the interactions from Polkadot to the rest of Web3. ### Sections - Introduction `#introduction` - Trustless Bridging `#trustless-bridging` - Bridging Components `#bridging-components` - Ethereum-Specific Support `#ethereum-specific-support` - Deployed Bridges `#deployed-bridges` - Where to Go Next `#where-to-go-next` --- ## Chain Data https://docs.polkadot.com/reference/parachains/chain-data.md Learn how to expose and utilize chain data for blockchain applications. Discover runtime metadata, RPC APIs, and tools for efficient development. ### Sections - Introduction `#introduction` - Application Development `#application-development` - Understand Metadata `#understand-metadata` - Expose Runtime Information as Metadata `#expose-runtime-information-as-metadata` - Generate Metadata `#generate-metadata` - Retrieve Runtime Metadata `#retrieve-runtime-metadata` - Use Polkadot.js `#use-polkadotjs` - Use Curl `#use-curl` - Use Subxt `#use-subxt` - Client Applications and Metadata `#client-applications-and-metadata` - Metadata Format `#metadata-format` - Pallets `#pallets` - Extrinsic `#extrinsic` - Included RPC APIs `#included-rpc-apis` - Additional Resources `#additional-resources` --- ## Collectives Chain https://docs.polkadot.com/reference/polkadot-hub/collectives-and-daos.md Learn how the Collectives chain provides infrastructure for governance organizations, enabling decentralized network stewardship and decision-making. ### Sections - Introduction `#introduction` - Key Collectives `#key-collectives` --- ## Cryptography https://docs.polkadot.com/reference/parachains/cryptography.md A concise guide to cryptography in blockchain, covering hash functions, encryption types, digital signatures, and elliptic curve applications. ### Sections - Introduction `#introduction` - Hash Functions `#hash-functions` - Key Properties of Hash Functions `#key-properties-of-hash-functions` - Blake2 `#blake2` - Types of Cryptography `#types-of-cryptography` - Symmetric Cryptography `#symmetric-cryptography` - Asymmetric Cryptography `#asymmetric-cryptography` - Trade-offs and Compromises `#trade-offs-and-compromises` - Digital Signatures `#digital-signatures` - Example of Creating a Digital Signature `#example-of-creating-a-digital-signature` - Elliptic Curve `#elliptic-curve` - Various Implementations `#various-implementations` --- ## Data Encoding https://docs.polkadot.com/reference/parachains/data-encoding.md SCALE codec enables fast, efficient data encoding, ideal for resource-constrained environments like Wasm, supporting custom types and compact encoding. ### Sections - Introduction `#introduction` - SCALE Codec `#scale-codec` - Encode `#encode` - Decode `#decode` - CompactAs `#compactas` - HasCompact `#hascompact` - EncodeLike `#encodelike` - Data Types `#data-types` - Encode and Decode Rust Trait Implementations `#encode-and-decode-rust-trait-implementations` - SCALE Codec Libraries `#scale-codec-libraries` --- ## Data Storage https://docs.polkadot.com/reference/polkadot-hub/data-storage.md Technical reference for the Polkadot Bulletin Chain, a specialized data storage chain with IPFS-compatible content addressing for the Polkadot ecosystem. ### Sections - Use Cases `#use-cases` - Key Concepts `#key-concepts` - Authorization `#authorization` - Who Grants Authorization `#who-grants-authorization` - Account Authorization `#account-authorization` - Preimage Authorization `#preimage-authorization` - Capacity Planning `#capacity-planning` - Transaction Storage Pallet `#transaction-storage-pallet` - IPFS Integration and Data Retrieval `#ipfs-integration-and-data-retrieval` - How It Works `#how-it-works` - Retrieval Methods `#retrieval-methods` - Data Lifecycle `#data-lifecycle` - Size Limits `#size-limits` - Network Endpoints `#network-endpoints` - Where to Go Next `#where-to-go-next` --- ## Dual Virtual Machine Stack https://docs.polkadot.com/smart-contracts/for-eth-devs/dual-vm-stack.md Compare Polkadot’s dual smart contract VMs—REVM for EVM compatibility and PolkaVM for RISC-V performance, flexibility, and efficiency. ### Sections - Introduction `#introduction` - REVM Backend `#revm-backend` - Key Benefits `#key-benefits` - How It Works `#how-it-works` - Architecture `#architecture` - Revive Pallet `#revive-pallet` - Alternative: PVM Backend `#alternative-pvm-backend` - Where To Go Next `#where-to-go-next` --- ## Elastic Scaling https://docs.polkadot.com/reference/parachains/consensus/elastic-scaling.md Learn how elastic scaling in Polkadot boosts parachain throughput, reduces latency, and supports dynamic, cost-efficient resource allocation. ### Sections - Introduction `#introduction` - How Elastic Scaling Works `#how-elastic-scaling-works` - Benefits of Elastic Scaling `#benefits-of-elastic-scaling` - Use Cases `#use-cases` - Handling Sudden Traffic Spikes `#handling-sudden-traffic-spikes` - Supporting Early-Stage Growth `#supporting-early-stage-growth` - Scaling Massive IoT Networks `#scaling-massive-iot-networks` - Powering Real-Time, Low-Latency Systems `#powering-real-time-low-latency-systems` --- ## EVM vs PVM https://docs.polkadot.com/smart-contracts/for-eth-devs/evm-vs-pvm.md Compares EVM and PVM, highlighting key architectural differences, gas models, memory management, and account handling while ensuring Solidity compatibility. ### Sections - Introduction `#introduction` - Core Virtual Machine Architecture `#core-virtual-machine-architecture` - High-Level Architecture Comparison `#high-level-architecture-comparison` - Gas Model `#gas-model` - Dynamic Gas Value Scaling `#dynamic-gas-value-scaling` - Multi-Dimensional Resource Metering `#multi-dimensional-resource-metering` - Memory Management `#memory-management` - Current Memory Limits `#current-memory-limits` - Account Management - Existential Deposit `#account-management-existential-deposit` - Account Management Comparison `#account-management-comparison` - Contract Deployment `#contract-deployment` - Solidity and YUL IR Translation Incompatibilities `#solidity-and-yul-ir-translation-incompatibilities` - Contract Code Structure `#contract-code-structure` - Solidity-Specific Differences `#solidity-specific-differences` - YUL Function Translation Differences `#yul-function-translation-differences` - Unsupported Operations `#unsupported-operations` - Compilation Pipeline Considerations `#compilation-pipeline-considerations` - Memory Pointer Limitations `#memory-pointer-limitations` --- ## Gas Model on the Polkadot Hub https://docs.polkadot.com/smart-contracts/for-eth-devs/gas-model.md Learn how gas estimation, pricing, and weight mapping work in the Polkadot Hub. ### Sections - Introduction `#introduction` - Understanding Resources in the Polkadot Hub `#understanding-resources-in-the-polkadot-hub` - Gas vs Weight `#gas-vs-weight` - How Gas Estimation Works `#how-gas-estimation-works` - Dynamic Gas Pricing `#dynamic-gas-pricing` - Transaction Execution Flow `#transaction-execution-flow` - Conclusion `#conclusion` --- ## Inclusion Pipeline https://docs.polkadot.com/reference/parachains/consensus/inclusion-pipeline.md Learn how Polkadot validates parachain blocks through the Inclusion Pipeline, detailing context, generation, backing, and inclusion stages. ### Sections - Introduction `#introduction` - Pipeline Stages `#pipeline-stages` - Context `#context` - Generation `#generation` - Backing `#backing` - Inclusion `#inclusion` --- ## Interoperability https://docs.polkadot.com/reference/parachains/interoperability.md Explore the importance of interoperability in the Polkadot ecosystem, covering XCM, bridges, and cross-chain communication. ### Sections - Introduction `#introduction` - Why Interoperability Matters `#why-interoperability-matters` - Key Mechanisms for Interoperability `#key-mechanisms-for-interoperability` - Cross-Consensus Messaging (XCM): The Backbone of Communication `#cross-consensus-messaging-xcm-the-backbone-of-communication` - Bridges: Connecting External Networks `#bridges-connecting-external-networks` - The Polkadot Advantage `#the-polkadot-advantage` - Looking Ahead `#looking-ahead` --- ## Networks https://docs.polkadot.com/reference/parachains/networks.md Explore Polkadot's networks, with Paseo as the official Polkadot TestNet for parachain and dApp development, plus Kusama and Westend for specialized use cases. ### Sections - Introduction `#introduction` - Network Overview `#network-overview` - Recommended Development Path `#recommended-development-path` - Alternative Networks `#alternative-networks` - Polkadot MainNet `#polkadot-mainnet` - Polkadot TestNet (Paseo) `#polkadot-testnet-paseo` - Other Networks `#other-networks` - Kusama Network `#kusama-network` - Westend `#westend` - Local Test Networks `#local-test-networks` - Zombienet `#zombienet` - Chopsticks `#chopsticks` --- ## Node and Runtime https://docs.polkadot.com/reference/parachains/node-and-runtime.md Learn how Polkadot SDK-based nodes function, how the client and runtime are separated, and how they communicate using SCALE-encoded data. ### Sections - Introduction `#introduction` - Architectural Principles `#architectural-principles` - Advantages of this Architecture `#advantages-of-this-architecture` - Node (Client) `#node-client` - Runtime `#runtime` - Characteristics `#characteristics` - Key Functions `#key-functions` - Communication Between Node and Runtime `#communication-between-node-and-runtime` - Runtime APIs `#runtime-apis` - Host Functions `#host-functions` --- ## On-Chain Governance Overview https://docs.polkadot.com/reference/governance.md Discover Polkadot’s cutting-edge OpenGov system, enabling transparent, decentralized decision-making through direct democracy and flexible governance tracks. ### Sections - Introduction `#introduction` - Governance Evolution `#governance-evolution` - OpenGov Key Features `#opengov-key-features` - Origins and Tracks `#origins-and-tracks` - Referendums `#referendums` - Vote on Referendums `#vote-on-referendums` - Delegate Voting Power `#delegate-voting-power` - Cancel a Referendum `#cancel-a-referendum` - Additional Resources `#additional-resources` --- ## Origins and Tracks https://docs.polkadot.com/reference/governance/origins-tracks.md Explore Polkadot's OpenGov origins and tracks system, defining privilege levels, decision processes, and tailored pathways for network proposals. ### Sections - Introduction `#introduction` - Origins `#origins` - Tracks `#tracks` - Additional Resources `#additional-resources` --- ## Overview of the Polkadot Relay Chain https://docs.polkadot.com/reference/polkadot-hub/consensus-and-security/relay-chain.md Explore Polkadot's core architecture, including its multi-chain vision, shared security, and the DOT token's governance and staking roles. ### Sections - Introduction `#introduction` - Polkadot 1.0 `#polkadot-10` - High-Level Architecture `#high-level-architecture` - Polkadot's Additional Functionalities `#polkadots-additional-functionalities` - Polkadot's Resilience `#polkadots-resilience` - Polkadot's Blockspace `#polkadots-blockspace` - DOT Token `#dot-token` - Redenomination of DOT `#redenomination-of-dot` - The Planck Unit `#the-planck-unit` - Uses for DOT `#uses-for-dot` - JAM and the Road Ahead `#jam-and-the-road-ahead` --- ## Parachain Consensus https://docs.polkadot.com/reference/parachains/consensus.md Understand how the blocks authored by parachain collators are secured by the relay chain validators and how the parachain transactions achieve finality. ### Sections - Introduction `#introduction` - The Role of Collators `#the-role-of-collators` - Consensus and Validation `#consensus-and-validation` - Path of a Parachain Block `#path-of-a-parachain-block` - Where to Go Next `#where-to-go-next` --- ## People Chain https://docs.polkadot.com/reference/polkadot-hub/people-and-identity.md Learn how People chain secures decentralized identity management, empowering users to control and verify digital identities without central authorities. ### Sections - Introduction `#introduction` - Identity Management System `#identity-management-system` - Sub-Identities `#sub-identities` - Verification Process `#verification-process` - Judgment Requests `#judgment-requests` - Judgment Classifications `#judgment-classifications` - Registrars `#registrars` - Where to Go Next `#where-to-go-next` --- ## Polkadot Hub Assets https://docs.polkadot.com/reference/polkadot-hub/assets.md Learn about asset management on Polkadot Hub, including on-chain assets, foreign asset integration, and XCM for cross-chain asset transfers. ### Sections - Introduction `#introduction` - Why Use Polkadot Hub? `#why-use-polkadot-hub` - Types of Assets `#types-of-assets` - Asset Structure `#asset-structure` - Common Asset IDs `#common-asset-ids` - How Native Assets Work `#how-native-assets-work` - Asset Operations `#asset-operations` - Roles and Permissions `#roles-and-permissions` - Freezing Assets `#freezing-assets` - Delegated Transfers `#delegated-transfers` - How Foreign Assets Work `#how-foreign-assets-work` - Moving Assets Across Chains `#moving-assets-across-chains` - Where to Go Next `#where-to-go-next` --- ## Polkadot Hub Overview https://docs.polkadot.com/reference/polkadot-hub.md Learn how Polkadot Hub serves as the entry point to Polkadot, providing access to smart contracts, staking, governance, identity management, and cross-ecosystem interoperability. ### Sections - Introduction `#introduction` - Polkadot Hub Capabilities `#polkadot-hub-capabilities` - Core Components `#core-components` - Smart Contracts `#smart-contracts` - Asset Management `#asset-management` - People Chain `#people-chain` - Bridge Hub `#bridge-hub` - Consensus & Security `#consensus-security` - Collectives & DAOs `#collectives-daos` - Where to Go Next `#where-to-go-next` --- ## Polkadot Hub Smart Contracts https://docs.polkadot.com/reference/polkadot-hub/smart-contracts.md Learn how Polkadot Hub supports smart contracts through the REVM, a Rust-based Ethereum Virtual Machine compatible runtime. ### Sections - Introduction `#introduction` - REVM Smart Contracts `#revm-smart-contracts` - PVM Smart Contracts `#pvm-smart-contracts` - Where to Go Next `#where-to-go-next` --- ## Polkadot SDK Accounts https://docs.polkadot.com/reference/parachains/accounts.md Learn about account structures, balances, and address formats in the Polkadot SDK, including how to manage lifecycle, references, and balances. ### Sections - Introduction `#introduction` - Account Data Structure `#account-data-structure` - Account `#account` - Account Info `#account-info` - Account Reference Counters `#account-reference-counters` - Account Balance Types `#account-balance-types` - Balance Types `#balance-types` - Locks `#locks` - Balance Types on Polkadot.js `#balance-types-on-polkadotjs` - Address Formats `#address-formats` - Basic Format `#basic-format` - Address Type `#address-type` - Address Length `#address-length` - Checksum Types `#checksum-types` - Validating Addresses `#validating-addresses` --- ## Proof of Stake Consensus https://docs.polkadot.com/reference/polkadot-hub/consensus-and-security/pos-consensus.md Explore Polkadot's consensus protocols for secure, scalable, and decentralized network operation, including NPoS, BABE, GRANDPA, and BEEFY. ### Sections - Introduction `#introduction` - Nominated Proof of Stake `#nominated-proof-of-stake` - Hybrid Consensus `#hybrid-consensus` - Block Production - BABE `#block-production-babe` - Validator Participation `#validator-participation` - Additional Resources `#additional-resources` - Finality Gadget - GRANDPA `#finality-gadget-grandpa` - Probabilistic vs. Provable Finality `#probabilistic-vs-provable-finality` - Additional Resources `#additional-resources-2` - Fork Choice `#fork-choice` - Additional Resources `#additional-resources-3` - Bridging - BEEFY `#bridging-beefy` --- ## Randomness https://docs.polkadot.com/reference/parachains/randomness.md Explore the importance of randomness in PoS blockchains, focusing on Polkadot’s VRF-based approach to ensure fairness and security in validator selection. ### Sections - Introduction `#introduction` - VRF `#vrf` - How VRF Works `#how-vrf-works` - RANDAO `#randao` - VDFs `#vdfs` - Additional Resources `#additional-resources` --- ## Runtime API Calls https://docs.polkadot.com/chain-interactions/query-data/runtime-api-calls.md Learn how to call Polkadot runtime APIs to access the Wasm runtime and retrieve computed results using PAPI, Polkadot.js, Dedot, Python, and Subxt. ### Sections - Introduction `#introduction` - Call Runtime APIs `#call-runtime-apis` - Available Runtime APIs `#available-runtime-apis` - Where to Go Next `#where-to-go-next` --- ## Technical Reference Overview https://docs.polkadot.com/reference.md Learn about Polkadot's technical architecture, governance framework, parachain ecosystem, and the tools you need to build and interact with the network. ### Sections - Introduction `#introduction` - Polkadot Hub `#polkadot-hub` - Parachains `#parachains` - On-Chain Governance `#on-chain-governance` - Glossary `#glossary` - Tools `#tools` - Where to Go Next `#where-to-go-next` --- ## Transactions https://docs.polkadot.com/reference/parachains/blocks-transactions-fees/transactions.md Learn how to construct, submit, and validate transactions in the Polkadot SDK, covering signed, unsigned, and inherent types of transactions. ### Sections - Introduction `#introduction` - What Is a Transaction? `#what-is-a-transaction` - Signed Transactions `#signed-transactions` - Unsigned Transactions `#unsigned-transactions` - Inherent Transactions `#inherent-transactions` - Transaction Formats `#transaction-formats` - Types of Transaction Formats `#types-of-transaction-formats` - Signed Transaction Data Structure `#signed-transaction-data-structure` - Signed Extensions `#signed-extensions` - Transaction Construction `#transaction-construction` - Construct a Signed Transaction `#construct-a-signed-transaction` - Transaction Encoding `#transaction-encoding` - Customize Transaction Construction `#customize-transaction-construction` - Lifecycle of a Transaction `#lifecycle-of-a-transaction` - Define Transaction Properties `#define-transaction-properties` - Process on a Block Authoring Node `#process-on-a-block-authoring-node` - Validate and Queue `#validate-and-queue` - Transaction Ordering and Priority `#transaction-ordering-and-priority` - Transaction Execution `#transaction-execution` - Transaction Mortality `#transaction-mortality` - Unique Identifiers for Extrinsics `#unique-identifiers-for-extrinsics` - Additional Resources `#additional-resources` --- ## Transactions and Fees on Asset Hub https://docs.polkadot.com/smart-contracts/for-eth-devs/blocks-transactions-fees.md Explore how Asset Hub smart contracts handle blocks, transactions, and fees with EVM compatibility, supporting various Ethereum transaction types. ### Sections - Introduction `#introduction` - Smart Contract Blocks `#smart-contract-blocks` - Smart Contract Transactions `#smart-contract-transactions` - EVM Transaction Types `#evm-transaction-types` - Fees and Gas `#fees-and-gas` - Gas Model Overview `#gas-model-overview` - Fee Components `#fee-components` - Gas Calculation and Conversion `#gas-calculation-and-conversion` --- ## Transactions Weights and Fees https://docs.polkadot.com/reference/parachains/blocks-transactions-fees/fees.md Overview of transaction weights and fees in Polkadot SDK chains, detailing how fees are calculated using a defined formula and runtime specifics. ### Sections - Introductions `#introductions` - How Fees are Calculated `#how-fees-are-calculated` - Using the Transaction Payment Pallet `#using-the-transaction-payment-pallet` - Understanding the Inclusion Fee `#understanding-the-inclusion-fee` - Accounts with an Insufficient Balance `#accounts-with-an-insufficient-balance` - Fee Multipliers `#fee-multipliers` - Transactions with Special Requirements `#transactions-with-special-requirements` - Default Weight Annotations `#default-weight-annotations` - Weights and Database Read/Write Operations `#weights-and-database-readwrite-operations` - Dispatch Classes `#dispatch-classes` - Dynamic Weights `#dynamic-weights` - Post Dispatch Weight Correction `#post-dispatch-weight-correction` - Custom Fees `#custom-fees` - Custom Weights `#custom-weights` - Additional Resources `#additional-resources`