Welcome to the Polkadot BTC-Relay documentation!

Introduction

• BTC-Relay at a Glance
  • Overview
  • How to Use this Document
• BTC-Relay Architecture
  • Actors
  • Components
• Bitcoin Data Model
  • Block Headers
  • Transactions
  • Inputs
  • Outputs
• Accepted Bitcoin Transaction Format
  • P2PKH / P2WPKH
  • OP_RETURN

Specification

• Data Model
  • Types
  • Constants
  • Structs
  • Data Structures
• Functions: Storage and Verification
  • initialize
  • storeBlockHeader
  • checkAndDoReorg
  • verifyBlockHeader
  • verifyTransactionInclusion
  • validateTransaction
  • flagBlockError
  • clearBlockError
• Functions: Utils
  • sha256d
  • concatSha256d
  • nBitsToTarget
  • checkCorrectTarget
  • computeNewTarget
  • computeMerkle
  • calculateDifficulty
  • getForkIdByBlockHash
  • incrementChainCounter
• Functions: Parser
  • Block Header
  • Transactions
• Events
  • Initialized
  • StoreMainChainHeader
  • StoreForkHeader
  • ChainReorg
  • VerifyTransaction
  • ValidateTransaction
• Error Codes

Security and Performance

• Security Analysis
  • Security Parameter k
  • Liveness Failures
  • Safety Failures
  • Hard and Soft forks
• Performance and Costs
  • Estimation of Storage Costs
  • BTC-Relay Optimizations

All the rest

• License
• Interlay