LogoLogo
LogoLogo
  • Intro
    • Welcome
    • The Benefits of BSV Blockchain
    • What Can I Do?
    • Overview of GitHub repositories
    • Quick Start
  • Protocol
    • Introduction
    • BSV Blockchain
      • Blocks
      • Transactions
      • Proof of Work
      • Capabilities
      • Economic Model of Governance
      • Digital Asset Recovery
    • Network Policies
      • High-Level Architecture
      • Mining
      • Standard and Local Policies
      • Consensus Rules
      • Local Policies
    • Node Operations
      • Node Software
      • Bitcoin Server Network (BSN)
      • ChainTracker
      • Transaction Validation
      • UTXO Storage
      • Mempool
      • Block Assembler
      • Block Validation
      • Mining Software
      • Pruning transactions
      • Responsibilities of a Node
    • SPV Wallets, Overlays and SPV Processes
      • Simplified Payment Verification (SPV)
      • Instant Payments
      • Integrity Checks
      • SPV Wallets & Overlays
    • Transaction Lifecycle
      • Transaction Inputs and Outputs
      • Script
      • Transaction Flow
      • Constructing a transaction
      • Sequence Number and Time Locking
      • Transaction Templates
      • Transaction Processing
      • Opcodes used in Script
    • Privacy
      • Keys and Identity
      • Private vs Anonymous
      • Digital Signatures
      • Privacy on the Public Blockchain
  • Network Access Rules
    • Rules
      • Table of Contents
      • Background to the Rules
      • PART I - MASTER RULES
      • PART II - GENERAL RULES
      • PART III - ENFORCEMENT RULES
      • PART IV - DISPUTE RESOLUTION RULES
      • PART V - INTERPRETIVE RULES
    • FAQs
      • Miners
      • Professionals
      • Users
  • Important Concepts
    • High Level
      • Web3
      • Timestamping
      • SPV
      • UTXO vs Account Based
      • Linked Keys
      • Smart Contracts
    • Details
      • Hash Functions
      • Merkle Trees
      • Sighash Flags
      • Script
      • SPV
        • Deep Dive
        • Payments Flow
        • Data Models
        • Broadcasting
  • Network Topology
    • Mandala Upgrade
    • Nodes
      • SV Node
        • Architecture
        • System Requirements
        • Installation
          • SV Node
            • Configuration
            • AWS Volumes Setup
            • DDOS Mitigation
            • Docker
            • Genesis Settings
            • GetMiningCandidate
            • GKE
            • Network Environments
              • Regtest
              • STN
              • Testnet
        • Alert System
          • Alert Messages
          • Running the Alert System
            • Startup Script
          • Webhooks
        • RPC Interface
          • RPC Methods
        • Frequently Asked Questions
          • Blocks
          • Initial Block Download
          • Transactions
          • Log File Warnings
          • Safe Mode
          • Bug Bounty
        • Chronicle Release
      • Teranode
    • Overlay Services
      • Overlay Example
    • SPV Wallet
      • Quickstart
      • Key Concepts
      • AWS Deployment
        • Installation
        • Manage & Maintain
        • Update
        • Delete
      • Components
        • SPV Wallet Server
        • Storage
        • Web Admin
        • Block Headers Service
        • Web App & API
      • Who is it for?
      • Functionality & Roadmap
      • Contribute
      • Developers Guide
        • SPV Wallet
          • Authentication
          • Configuration
          • Notification
        • Go Client
          • Authentication
        • JS Client
          • Authentication
        • Admin
        • Keygen
        • Block Headers Service
          • Authentication
          • Configuration
      • Additional Components
  • paymail
    • Overview
    • BRFC Specifications
      • Specification Documents
      • BRFC ID Assignment
    • Service Discovery
      • Host Discovery
      • Capability Discovery
    • Public Key Infrastructure
    • Payment Addressing
      • Basic Address Resolution
      • Sender Validation
      • Receiver Approvals
      • PayTo Protocol Prefix
    • Verify Public Key Owner
    • Recommendations
  • Guides
    • Local Blockchain Stack
      • Mockchain Stack
    • Business Use Cases
      • Creating a Tranche of Event Tickets
    • SDKs
      • Concepts
        • BEEF
        • Fees
        • SPV
        • Transactions
        • Op Codes
        • Script Templates
        • Signatures
        • Verification
      • TypeScript
        • Node, CommonJS
        • React
        • Low Level
          • Verification
          • ECDH
          • Numbers & Points
          • Signatures
          • 42
          • ECDSA
          • Hmacs
          • Keys
          • Scripts
        • Examples
          • Creating a Simple Transaction
          • Verifying a BEEF Structure
          • Creating Transactions with Inputs, Outputs and Templates
          • Creating the R-puzzle Script Template
          • Message Encryption and Decryption
          • Message Signing
          • Building a Custom Transaction Broadcast Client
          • Verifying Spends with Script Intrepreter
          • BIP32 Key Derivation with HD Wallets
          • Using Type 42 Key Derivation for Bitcoin Wallet Management
          • Creating a Custom Transaction Fee Model
          • Building a Pulse Block Headers Client
          • Using ECIES Encryption
      • Go
        • Examples
          • Simple Tx
          • Keys
          • Encryption
          • Broadcasting
          • Inscribing
          • Data Markers
          • Linked Keys
          • ECIES
          • Fees
          • HD Keys
          • Headers
          • Secure Messages
          • Merkle Path Verification
      • Python
        • Examples
          • Simple Tx
          • Verifying BEEF
          • Complex Tx
          • Script Templates
          • Encryption
          • Message Signing
          • Building A Custom Broadcaster
          • HD Wallets
          • Linked Keys
          • Fees
          • Merkle Path Verification
          • ECIES
  • BSV Academy
    • Getting Started
    • BSV Basics: Protocol and Design
      • Introduction
        • Bit-Coin
      • The BSV Ledger
        • The Ledger
        • Triple Entry Accounting
        • Example
      • Coins and Transactions
        • Coins
        • Transactions
        • Transaction Fees
      • Theory
      • Conclusion
    • BSV Enterprise
      • Introduction
      • About BSV Blockchain
        • Introduction
        • Safe, Instant Transactions at a Predictably Low Cost
          • Reliably Low Fees
          • Comparison to Legacy Transaction Systems
          • Payment Channels
        • Scalability to Accommodate Global Demand
          • Big Blocks Show Big Potential
        • A Plan for Regulatory Acceptance
          • Ready-made Compliance
          • The Open BSV License
        • Protocol Stability
          • Building Foundations on a Bedrock of Stone
      • Technical Details
        • The Network
          • The Small World Network
          • Robust In Its Unstructured Simplicity
        • The Bitcoin SV Node Client
          • Teranode - The Future of BSV
        • The Protocol - Simple, Robust and Unbounded
          • What is the BSV Protocol?
        • Proof of Work
          • The Algorithm
          • Efficiency of Proof of Work
        • Privacy and Identity
        • Permissions and Privacy
      • Resources and Tools
        • The Technical Standards Comittee
          • TSC Principles
          • Standard Development Process
          • Status of Current and In-progress Standards
        • The Working Blockchain
          • Pruning to Create a Working Blockchain
          • Building a Working Blockchain from a List of Block Headers
          • A World View Backed by Proof of Work
    • Hash Functions
      • What are Hash Functions?
        • The Differences Between Hashing and Encryption
        • The Three Important Properties of Hash Functions
        • The Hash Functions Found in BSV
      • Base58 and Base58Check
        • What is Base58 and Why Does Bitcoin use it?
        • What is Base58 and How Does BSV use it?
      • SHA256
        • BSV Transactions and SHA-256
        • BSV Blocks and SHA-256
        • Proof-of-Work and HASH-256
      • Walkthrough Implementation of SHA-256 in Golang
        • Overview of SHA-256
        • SHA-256 Input and Processing
        • SHA-256 Compression
        • SHA-256 Final Value Construction and Output
      • RIPEMD-160
        • BSV Addresses & WIFs
      • Walkthrough Implementation of RIPEMD-160 in Golang
        • Overview of RIPEMD-160
        • RIPEMD-160 Input and Processing
        • RIPEMD-160 Compression
        • RIPEMD-160 Final Value Construction and Output
      • Doubla Hashing and BSV's Security
        • Why is Double Hashing Used in BSV
        • Hash Functions and BSV's Security Model
    • Merkle Trees
      • The Merkle Tree
        • What is a Merkle Tree?
        • Why use a Merkle Tree?
        • Merkle Trees in Action
      • Merkles Trees in BSV
        • The Data Elements
        • Transaction Merkle Trees
        • Transaction Merkle Trees in Action
      • Merkle Trees and the Block Header
        • What is the Block Header
        • The Hash Puzzle
        • Proof-of-Work in Action
      • Merkle trees and Verifying Proof of Work
        • Broadcasting the Block
        • The Coinbase Transaction
        • Data Integrity of the Block
        • Saving Disk Space
      • Standarised Merkle Proof
        • What is a Merkle Proof?
        • The BSV Unified Merkle Path (BUMP) Standard
        • Simple and Composite Proofs
      • Merkle Trees and Simplified Payment Verification
        • SPV
        • Offline Payments
    • Digital Signatures
      • What are Digital Signatures
        • Background
        • Introduction
        • Digital Signatures Protocol
        • Properties of Digital Signatures
      • ECDSA Prerequisites
        • Disclaimer
        • Modular Arithmetic
        • Groups, Rings and Finite Fields
        • Discrete Logarithm Problem
        • Elliptic Curve Cryptography (ECC)
        • Discrete Logarithm Problem with Elliptic Curves
      • ECDSA
        • Introduction
        • ECDSA
        • Further Discussion
      • BSV and Digital Signatures
        • Introduction
        • BSV Transaction
        • ECDSA (secp256k1) for BSV Transaction
        • Summary
        • Signed Messages
        • Miner Identification and Digital Signatures
    • BSV Theory
      • Abstract
        • Peer-to-Peer Cash
        • Digital Signatures and Trusted Third Parties
        • Peer-to-Peer Network
        • Timechain and Proof-of-Work
        • CPU Power
        • Cooperation in the Network
        • Network Structure
        • Messaging Between Nodes
      • Introduction
        • Commerce on the Internet
        • Non Reversible Transactions
        • Privacy in Commerce
        • The Paradigm of Fraud Acceptance
        • What is Needed...
        • Protecting Sellers From Fraud
        • Proposed Solution
        • Security and Honesty
      • Transactions
        • Electronic Coins
        • Spending a Coin
        • Payee Verification
        • Existing Solutions
        • First Seen Rule
        • Broadcasting Transactions
        • Achieving Consensus
        • Proof of Acceptance
      • Timestamp Server
        • Timestamped Hashes
        • A Chain of Timestamped Hashes
      • Proof of Work
        • Hashcash
        • Scanning Random Space
        • Nonce
        • Immutable Work
        • Chain Effort
        • One CPU, One Vote
        • The Majority Decision
        • The Honest Chain
        • Attacking the Longest Chain
        • Controlling the Block Discovery Rate
      • Network
        • Running the Network
        • The Longest Chain
        • Simultaneous Blocks
        • Breaking the Tie
        • Missed Messages
      • Incentive
        • The Coinbase Transaction
        • Coin Distribution
        • Mining Analogy
        • Transaction Fees
        • The End of Inflation
        • Encouraging Honesty
        • The Attacker's Dilemma
      • Reclaiming Disk Space
        • Spent Transactions
        • The Merkle Tree
        • Compacting Blocks
        • Block Headers
      • Simplified Payment Verification
        • Full Network Nodes
        • Merkle Branches
        • Transaction Acceptance
        • Verification During Attack Situations
        • Maintaining an Attack
        • Invalid Block Relay System
        • Businesses Running Nodes
      • Combining and Splitting Value
        • Dynamically Sized Coins
        • Inputs and Outputs
        • A Typical Example
        • Fan Out
      • Privacy
        • Traditional Models
        • Privacy in Bitcoin
        • Public Records
        • Stock Exchange Comparison
        • Key Re-Use
        • Privacy - Assessment 2
        • Linking Inputs
        • Linking the Owner
      • Calculations
        • Attacking the Chain
        • Things the Attacker Cannot Achieve
        • The Only Thing an Attacker Can Achieve
        • The Binomial Random Walk
        • The Gambler's Ruin
        • Exponential Odds
        • Waiting For Confirmation
        • Attack Via Proof of Work
        • Vanishing Probabilities
      • Conclusion
        • Conclusion Explained
    • Introduction to Bitcoin Script
      • Chapter 1: About Bitcoin Script
        • 01 - Introduction
        • 02 - FORTH: A Precursor to Bitcoin Script
        • 03 - From FORTH to Bitcoin Script
        • 04 - Bitcoin's Transaction Protocol
        • 05 - Transaction Breakdown
        • 06 - nLockTime
        • 07 - The Script Evaluator
      • Chapter 2: Basic Script Syntax
        • 01 - Introduction
        • 02 - Rules Around Data and Scripting Grammar
        • 03 - The Stacks
      • Chapter 3: The Opcodes
        • 01 - Introduction
        • 02 - Constant Value and PUSHDATA Opcodes
        • 03 - IF Loops
        • 04 - OP_NOP, OP_VERIFY and its Derivatives
        • 05 - OP_RETURN
        • 06 - Stack Operations
        • 07 - Data transformation
        • 08 - Stack Data Queries
        • 09 - Bitwise transformations and Arithmetic
        • 10 - Cryptographic Functions
        • 11 - Disabled and Removed Opcodes
      • Chapter 4: Simple Scripts
        • 01 - Introduction
        • 01 - Pay to Public Key (P2PK)
        • 02 - Pay to Hash Puzzle
        • 03 - Pay to Public Key Hash (P2PKH)
        • 04 - Pay to MultiSig (P2MS)
        • 05 - Pay to MultiSignature Hash (P2MSH)
        • 06 - R-Puzzles
      • Chapter 5: OP_PUSH_TX
        • 01 - Turing Machines
        • 02 - Elliptic Curve Signatures in Bitcoin
        • 03 - OP_PUSH_TX
        • 04 - Signing and Checking the Pre-Image
        • 05 - nVersion
        • 06 - hashPrevouts
        • 07 - hashSequence
        • 08 - Outpoint
        • 09 - scriptLen and scriptPubKey
        • 10 - value
        • 11 - nSequence
        • 12 - hashOutputs
        • 13 - nLocktime
        • 14 - SIGHASH flags
      • Chapter 6: Conclusion
        • Conclusion
    • BSV Infrastructure
      • The Instructions
        • The Whitepaper
        • Steps to Run the Network
        • Step 1
        • Step 2
        • Step 3
        • Step 4
        • Step 5
        • Step 6
      • Rules and their Enforcement
        • Introduction
        • Consensus Rules
        • Block Consensus Rules
        • Transaction Consensus Rules
        • Script Language Rules
        • Standard Local Policies
      • Transactions, Payment Channels and Mempools
      • Block Assembly
      • The Small World Network
        • The Decentralisation of Power
        • Incentive Driven Behaviour
        • Lightspeed Propagation of Transactions
        • Ensuring Rapid Receipt and Propagation of New Blocks
        • Hardware Developments to Meet User Demand
        • Novel Service Delivery Methods
        • MinerID
      • Conclusion
  • Research and Development
    • BRCs
    • Technical Standards
  • Support & Contribution
    • Join Our Discord
    • GitHub
Powered by GitBook
On this page
  • Understanding Script Templates
  • Creating a Script Template
  • Conclusion

Was this helpful?

Edit on GitHub
Export as PDF
  1. Guides
  2. SDKs
  3. TypeScript
  4. Examples

Creating the R-puzzle Script Template

PreviousCreating Transactions with Inputs, Outputs and TemplatesNextMessage Encryption and Decryption

Last updated 1 year ago

Was this helpful?

This guide will provide information about the structure and functionality of script templates within the BSV SDK. Script templates are a powerful abstraction layer designed to simplify the creation and management of the scripts used in Bitcoin transactions. By understanding how these templates work, developers can leverage them to build more sophisticated and efficient blockchain applications. By the end of this example, you'll understand how the R-puzzle script template (P2RPH) was created.

Understanding Script Templates

A script template is essentially a blueprint for creating the locking and unlocking scripts that are crucial for securing and spending bitcoins. These templates encapsulate the logic needed to construct these scripts dynamically, based on the parameters passed to them. This approach allows for a modular and reusable codebase, where common scripting patterns can be defined once and then instantiated as needed across different transactions.

Locking Script

The locking script, or output script, specifies the conditions under which the bitcoins can be spent. In the BSV SDK, the lock function of a script template is responsible for generating this script. By abstracting the creation of locking scripts into a method that accepts parameters, developers can easily create diverse conditions for spending bitcoins without having to write the low-level script code each time.

For example, a locking script might require the presentation of a public key that matches a certain hash or the fulfillment of a multi-signature condition. The flexibility of passing parameters to the lock function enables the creation of locking scripts tailored to specific requirements. This example will require a signature created with a particular ephemeral K-value, .

Unlocking Script

The unlocking script, or input script, provides the evidence needed to satisfy the conditions set by the locking script. The unlock method in a script template not only generates this script but also offers two key functionalities — it's a function that returns an object with two properties:

  1. estimateLength: Before a transaction is signed and broadcast to the network, it's crucial to estimate its size to calculate the required fee accurately. The estimateLength function predicts the length of the unlocking script once it will be created, allowing developers to make informed decisions about fee estimation.

  2. sign: This function generates an unlocking script that includes the necessary signatures or data required to unlock the bitcoins. By accepting a transaction and an input index as arguments, it ensures that the unlocking script is correctly associated with the specific transaction input it intends to fund, allowing signatures to be scoped accordingly.

Creating a Script Template

To create a script template, developers define a class that adheres to the ScriptTemplate interface. This involves implementing the lock and unlock methods with the specific logic needed for their application.

Now that you understand the necessary components, here's the code for the R-puzzle script template:

import {
  OP, ScriptTemplate, LockingScript, UnlockingScript, Transaction,
  PrivateKey, TransactionSignature, sha256, ScriptChunk, BigNumber
} from '@bsv/sdk'

/**
 * RPuzzle class implementing ScriptTemplate.
 *
 * This class provides methods to create R Puzzle and R Puzzle Hash locking and unlocking scripts, including the unlocking of UTXOs with the correct K value.
 */
export default class RPuzzle implements ScriptTemplate {
  type: 'raw' | 'SHA1' | 'SHA256' | 'HASH256' | 'RIPEMD160' | 'HASH160' = 'raw'

  /**
   * @constructor
   * Constructs an R Puzzle template instance for a given puzzle type
   *
   * @param {'raw'|'SHA1'|'SHA256'|'HASH256'|'RIPEMD160'|'HASH160'} type Denotes the type of puzzle to create
   */
  constructor (type: 'raw' | 'SHA1' | 'SHA256' | 'HASH256' | 'RIPEMD160' | 'HASH160' = 'raw') {
    this.type = type
  }

  /**
   * Creates an R puzzle locking script for a given R value or R value hash.
   *
   * @param {number[]} value - An array representing the R value or its hash.
   * @returns {LockingScript} - An R puzzle locking script.
   */
  lock (value: number[]): LockingScript {
    const chunks: ScriptChunk[] = [
      { op: OP.OP_OVER },
      { op: OP.OP_3 },
      { op: OP.OP_SPLIT },
      { op: OP.OP_NIP },
      { op: OP.OP_1 },
      { op: OP.OP_SPLIT },
      { op: OP.OP_SWAP },
      { op: OP.OP_SPLIT },
      { op: OP.OP_DROP }
    ]
    if (this.type !== 'raw') {
      chunks.push({
        op: OP['OP_' + this.type]
      })
    }
    chunks.push({ op: value.length, data: value })
    chunks.push({ op: OP.OP_EQUALVERIFY })
    chunks.push({ op: OP.OP_CHECKSIG })
    return new LockingScript(chunks)
  }

  /**
   * Creates a function that generates an R puzzle unlocking script along with its signature and length estimation.
   *
   * The returned object contains:
   * 1. `sign` - A function that, when invoked with a transaction and an input index,
   *    produces an unlocking script suitable for an R puzzle locked output.
   * 2. `estimateLength` - A function that returns the estimated length of the unlocking script in bytes.
   *
   * @param {BigNumber} k — The K-value used to unlock the R-puzzle.
   * @param {PrivateKey} privateKey - The private key used for signing the transaction. If not provided, a random key will be generated.
   * @param {'all'|'none'|'single'} signOutputs - The signature scope for outputs.
   * @param {boolean} anyoneCanPay - Flag indicating if the signature allows for other inputs to be added later.
   * @returns {Object} - An object containing the `sign` and `estimateLength` functions.
   */
  unlock (
    k: BigNumber,
    privateKey: PrivateKey,
    signOutputs: 'all' | 'none' | 'single' = 'all',
    anyoneCanPay: boolean = false
  ): {
      sign: (tx: Transaction, inputIndex: number) => Promise<UnlockingScript>
      estimateLength: () => Promise<106>
    } {
    return {
      sign: async (tx: Transaction, inputIndex: number) => {
        if (typeof privateKey === 'undefined') {
          privateKey = PrivateKey.fromRandom()
        }
        let signatureScope = TransactionSignature.SIGHASH_FORKID
        if (signOutputs === 'all') {
          signatureScope |= TransactionSignature.SIGHASH_ALL
        }
        if (signOutputs === 'none') {
          signatureScope |= TransactionSignature.SIGHASH_NONE
        }
        if (signOutputs === 'single') {
          signatureScope |= TransactionSignature.SIGHASH_SINGLE
        }
        if (anyoneCanPay) {
          signatureScope |= TransactionSignature.SIGHASH_ANYONECANPAY
        }
        const otherInputs = [...tx.inputs]
        const [input] = otherInputs.splice(inputIndex, 1)
        if (typeof input.sourceTransaction !== 'object') {
          throw new Error(
            'The source transaction is needed for transaction signing.'
          )
        }
        const preimage = TransactionSignature.format({
          sourceTXID: input.sourceTransaction.id('hex') as string,
          sourceOutputIndex: input.sourceOutputIndex,
          sourceSatoshis: input.sourceTransaction.outputs[input.sourceOutputIndex].satoshis,
          transactionVersion: tx.version,
          otherInputs,
          inputIndex,
          outputs: tx.outputs,
          inputSequence: input.sequence,
          subscript: input.sourceTransaction.outputs[input.sourceOutputIndex].lockingScript,
          lockTime: tx.lockTime,
          scope: signatureScope
        })
        const rawSignature = privateKey.sign(sha256(preimage), undefined, true, k)
        const sig = new TransactionSignature(
          rawSignature.r,
          rawSignature.s,
          signatureScope
        )
        const sigForScript = sig.toChecksigFormat()
        const pubkeyForScript = privateKey.toPublicKey().encode(true) as number[]
        return new UnlockingScript([
          { op: sigForScript.length, data: sigForScript },
          { op: pubkeyForScript.length, data: pubkeyForScript }
        ])
      },
      estimateLength: async () => {
        // public key (1+33) + signature (1+71)
        // Note: We add 1 to each element's length because of the associated OP_PUSH
        return 106
      }
    }
  }
}

Conclusion

Script templates in the BSV SDK offer a structured and efficient way to handle the creation of locking and unlocking scripts in Bitcoin transactions. By encapsulating the logic for script generation and providing essential functionalities like signature creation and length estimation, script templates make it easier for developers to implement complex transactional logic. With these tools, template consumers can focus on the higher-level aspects of their blockchain applications, relying on the SDK to manage the intricacies of script handling.

In this example, RPuzzle defines custom logic for creating both locking and unlocking scripts. The opcodes, intermixed with the various template fields, enable end-users to implement R-puzzles into their applications without being concerned with these low-level details. Check out to see an example of this template used in a transaction.

an R-puzzle
this guide