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Core Concepts Overview

RGB is built on revolutionary distributed computing concepts that enable smart contracts on Bitcoin without modifying the blockchain itself. This section introduces the core architectural principles.

The RGB Paradigm​

RGB fundamentally reverses traditional blockchain validation through three key concepts:

1. Client-Side Validation​

Unlike traditional blockchains where every node validates every transaction, RGB uses client-side validation:

  • Only parties involved in a transaction validate its history
  • Validation data is transferred off-chain via consignments
  • Bitcoin blockchain contains only cryptographic commitments
  • Privacy is preserved as others can't see your transactions

Learn more about Client-Side Validation →

2. Bitcoin UTXO Binding​

RGB prevents double-spending by binding state to Bitcoin UTXOs:

  • Each RGB state is bound to a specific Bitcoin UTXO
  • Spending the UTXO commits the new RGB state
  • Bitcoin consensus prevents double-spending UTXOs
  • Therefore: RGB state cannot be double-spent
  • No RGB-specific consensus needed (Bitcoin handles it)

Learn more about UTXO binding →

3. PRISM Computing​

RGB implements Partially-Replicated Infinite State Machines (PRISM):

  • Not all participants replicate the entire state
  • Each party maintains only their relevant state fragment
  • State evolves as a directed acyclic graph (DAG)
  • Enables massive scalability

Learn more about PRISM Computing →

RGB Architecture Layers​

Key Components​

AluVM Virtual Machine​

RGB uses zk-AluVM, a revolutionary VM designed for zk-STARK compatibility:

  • 40 instructions total (vs thousands in traditional VMs)
  • Non-von-Neumann architecture
  • Read-once memory compatible with single-use seals
  • Turing-complete despite simplicity
  • Formally verifiable code analysis

Explore AluVM →

State Management​

RGB v0.12 unified all state into a single type of finite field elements:

  • Owned State: Rights controlled by Bitcoin script
  • Global State: Public information accessible to all
  • Metadata: Additional contract-specific data

Learn about State Management →

Bitcoin Integration​

RGB leverages Bitcoin through deterministic commitments:

  • Tapret: Taproot-based commitments (preferred)
  • Opret: OP_RETURN-based commitments (fallback)
  • MPC: Multi-Protocol Commitments for efficiency

Understand Bitcoin Integration →

Data Flow​

Contract Issuance​

Asset Transfer​

Design Principles​

Privacy by Design​

  • Original transaction details are never published
  • Only cryptographic hashes visible on-chain
  • State distributed only to relevant parties
  • Optional blinding for UTXO allocations

Scalability​

  • Validation complexity grows with personal history, not global state
  • Parallel validation across different assets
  • No blockchain bloat from smart contract execution
  • Lightning Network integration for instant transfers

Simplicity​

RGB v0.12 achieved dramatic simplification:

  • 4x reduction in codebase size
  • Single unified state type
  • 40-instruction VM
  • Easier to audit and verify

Bitcoin-Native​

  • No altcoins or separate consensus
  • Leverages Bitcoin's security
  • Compatible with Lightning Network
  • Uses existing Bitcoin primitives

RGB vs Traditional Smart Contracts​

AspectTraditional (Ethereum)RGB
ValidationGlobal (all nodes)Client-side (parties only)
State StorageOn-chain (public)Off-chain (private)
PrivacyMinimalStrong
ScalabilityLimitedMassive
FeesVariable, often highBitcoin TX fees only
ExecutionOn-chainOff-chain
BlockchainPurpose-builtBitcoin

Understanding RGB Through Use Cases​

Fungible Tokens (RGB20)​

Issue stablecoins, securities, utility tokens
↓
Transfer instantly on Lightning
↓
Maintain complete privacy
↓
Pay only Bitcoin transaction fees

Non-Fungible Tokens (RGB21)​

Create unique digital assets
↓
Attach rich metadata
↓
Transfer ownership via Bitcoin
↓
Prove authenticity through validation

Complex Contracts​

Write in Contractum language
↓
Compile to AluVM bytecode
↓
Execute validation logic
↓
Enforce rules via single-use seals

zk-STARK Future​

RGB v0.12 was designed for future zk-STARK integration:

Current: ~100 lines of validation code
↓
Future: Single zk-STARK proof
↓
Result: Constant-size validation
+ Ultimate privacy
+ Instant verification

Key Takeaways​

  1. Client-side validation keeps data off-chain and private
  2. Bitcoin UTXO binding leverages existing double-spend prevention
  3. PRISM computing enables massive scalability
  4. AluVM provides Turing-complete contract execution
  5. Bitcoin-native design leverages existing security
  6. zk-ready architecture prepares for zero-knowledge future

Next Steps​

Dive deeper into specific concepts:

Additional Resources​