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
  • Bitwise transformation opcodes
  • Checking bitwise outcomes
  • Arithmetic transformations
  • Boolean Shifts
  • Boolean Data Checks
  • Arithmetic value checks
  • Max, Min and Within

Was this helpful?

Edit on GitHub
Export as PDF
  1. BSV Academy
  2. Introduction to Bitcoin Script
  3. Chapter 3: The Opcodes

09 - Bitwise transformations and Arithmetic

Previous08 - Stack Data QueriesNext10 - Cryptographic Functions

Last updated 4 months ago

Was this helpful?

Bitcoin Script has a full array of bitwise/binary transformation and arithmetic opcodes.

Bitwise transformation opcodes

Bitwise transformation opcodes are used to perform bitwise transformations on data items on the stack.

Word
Input
Output
Description

OP_INVERT

in

out

Flips all of the bits in the input.

OP_AND

x1 x2

out

Boolean and between each bit in the inputs.

OP_OR

x1 x2

out

Boolean or between each bit in the inputs.

OP_XOR

x1 x2

out

Boolean exclusive or between each bit in the inputs.

Checking bitwise outcomes

To check Bitwise outcomes, the scripting language provides an equality checker. For these checks to return true, the values on the stack must be equal at a bitwise level - i.e. they must be the same value and the same size.

Word
Input
Output
Description

OP_EQUAL

x1 x2

True / false

Returns 1 if the inputs are exactly equal, 0 otherwise.

OP_EQUALVERIFY

x1 x2

Nothing / fail

Same as OP_EQUAL, but runs OP_VERIFY afterward.

Example 1:

<0x80> OP_AND <0x80> OP_EQUALVERIFY

This example checks that the first bit of the top stack item is 1 (0x80 = 0b10000000). If this condition is not met, the script will fail. The other bits are not evaluated. The top stack item must be 1 byte long or the script will fail.

Example 2:

<0x7f> OP_OR <0x7f> OP_EQUALVERIFY

This example checks that the first bit of the top stack item is 0 (0x7F = 0b01111111). If this condition is not met, the script will fail. The other bits are not evaluated. The top stack item must be 1 byte long or the script will fail.

Example 3:

OP_XOR <0x7F> OP_OR <0xFF> OP_EQUALVERIFY This example first applies an XOR function to two single byte values at the top of the stack. It then uses 0x7f OP_OR to check that only one of them had the first bit set, and excludes the remaining bits from the test. If this condition is not met, the script will fail. The stack items must be 1 byte long or the script will fail.

Arithmetic transformations

These operations perform arithmetic and other mathematical transformations on data items on the stack.

Word
Input
Output
Description

OP_NEGATE

in

out

The sign of the input is flipped.

OP_ABS

in

out

The input is made positive.

OP_ADD

a b

out

a is added to b.

OP_1ADD

in

out

1 is added to the input.

OP_SUB

a b

out

b is subtracted from a.

OP_1SUB

in

out

1 is subtracted from the input.

OP_NOT

in

out

If the input is 0 or 1, it is flipped. Otherwise the output will be 0.

OP_MUL

a b

out

a is multiplied by b.

OP_DIV

a b

out

a is divided by b.

OP_MOD

a b

out

Returns the remainder after dividing a by b.

Example 1:

OP_DUP OP_DUP OP_MUL OP_MUL OP_ABS

In this example, the number at the top of the stack is duplicated twice and then the three values are multiplied together to calculate the cube of the original value. The absolute value of the outcome is the final result.

Example 2:

OP_DUP OP_MUL <314> OP_MUL <100> OP_DIV <1,000,000>* OP_LESSTHANOREQUAL

OP_FALSE OP_RETURN

OP_ENDIF

In this example, a trusted IoT measurement device records and reports the radius of a circle. The script uses this value to calculate the circle's area using the equation Pi x r^2. If the circle is less than 1m^2 the script fails. Note that there are no floating point calculations in Bitcoin, so 314 is used to approximate Pi (3.14) and the resulting output divided by 100 to get a figure in m^2.

* For readability, <314>, <100> and <1,000,000> are shown as decimal numbers. To implement this example in script, the little endian integers 0x3A01, 0x64 and 0x40420F should be used respectively.

Example 3:

OP_DUP OP_SHA256 <1,000,000>* OP_MOD OP_NOTIF

<1>

OP_ELSE

<2>

OP_ENDIF

<pubkey1> <pubkey2> <2> OP_CHECKMULTISIG

* For readability <1,000,000> is shown as a decimal number. To implement this example in script, the little endian integer 0x40420F should be used.

In this example, the signing parties play a game where the first to find a signature that with a SHA256 hash that is divisible by 1 million can spend the output. To begin the game, the coin is spent into a non-final script using both keys which pays out equally. If one user finds a valid solution before the time expires, they can finalise the payment channel and spend the full amount to their own wallet.

Valid solutions to the script are as follows:

<x> <signature 1> (where signature 1 is divisible by 1,000,000)

<x> <signature 2> (where signature 2 is divisible by 1,000,000)

<x> <signature 1> <signature 2>

Boolean Shifts

Boolean shifts are used to shift the bits within a data item on the stack. There is no limit to the size of data item that these opcodes can be applied to.

Word
Input
Output
Description

OP_LSHIFT

a b

out

Logical left shift b bits. Sign data is discarded

OP_RSHIFT

a b

out

Logical right shift b bits. Sign data is discarded

Boolean Data Checks

These opcodes check inputs against Boolean and/or conditions. In all cases, any non-zero value is considered a true/1, while a zero value of any length bytevector is considered a false/0.

Word
Input
Output
Description

OP_BOOLAND

a b

out

If both a and b are not 0, the output is 1. Otherwise 0.

OP_BOOLOR

a b

out

If a or b is not 0, the output is 1. Otherwise 0.

Arithmetic value checks

These opcodes allow the script to check stack values against pre-set/expected results to create complex functionality.

Word
Input
Output
Description

OP_NUMEQUAL

a b

out

Returns 1 if the numbers are equal, 0 otherwise.

OP_NUMEQUALVERIFY

a b

Nothing / fail

Same as OP_NUMEQUAL, but runs OP_VERIFY afterward.

OP_NUMNOTEQUAL

a b

out

Returns 1 if the numbers are not equal, 0 otherwise.

OP_LESSTHAN

a b

out

Returns 1 if a is less than b, 0 otherwise.

OP_GREATERTHAN

a b

out

Returns 1 if a is greater than b, 0 otherwise.

OP_LESSTHANOREQUAL

a b

out

Returns 1 if a is less than or equal to b, 0 otherwise.

OP_GREATERTHANOREQUAL

a b

out

Returns 1 if a is greater than or equal to b, 0 otherwise.

Max, Min and Within

These opcodes allow the script to select a maximum or minimum value from a group, or to discover whether a value is within a range.

Word
Input
Output
Description

OP_MIN

a b

out

Returns the smaller of a and b.

OP_MAX

a b

out

Returns the larger of a and b.

OP_WITHIN

x min max

out

Returns 1 if x is within the specified range (left-inclusive), 0 otherwise.