# Architecture Overview

Tortuga is a multi-chain RWA platform with the Internet Computer serving as the master ledger and Chain Fusion enabling native token representation across EVM, Solana, and Cosmos ecosystems.

# Design Principles

Principle	Implementation
Single Source of Truth	Master Ledger on ICP holds canonical state
No Bridges	Chain Fusion uses threshold signatures, not wrapped tokens
Compliance First	KYC enforced at protocol level, not application level
Chain Agnostic	Investors choose their preferred chain

# High-Level Architecture

flowchart TB
    subgraph ICP["Internet Computer"]
        ML[Master Ledger]
        KYC[KYC Registry]
        YLD[Yield Distributor]
        CF[Chain Fusion Orchestrator]
    end

    subgraph External["External Chains"]
        EVM[EVM Contracts]
        SOL[Solana Programs]
        COSM[Cosmos Modules]
    end

    subgraph Infra["Infrastructure"]
        SUMSUB[Sumsub KYC]
        ISSUER[Issuer Backend]
    end

    ISSUER --> ML
    SUMSUB --> KYC
    KYC --> ML
    ML <--> CF
    CF <--> EVM
    CF <--> SOL
    CF <--> COSM
    ML --> YLD

# Component Overview

# Master Ledger

The canonical record of all tokenized bonds, holder balances, and transaction history. All cross-chain state ultimately syncs back here.

# Chain Fusion

ICP's native cross-chain technology using threshold cryptography. Enables direct signing of transactions on external chains without bridges or wrapped tokens.

# Cross-Chain Operations

Technical flows for minting, burning, and transferring tokens across chains. Includes signature schemes and message formats.

# Data Flow

flowchart LR
    subgraph Issuance
        BOND[Bond Created]
        META[Metadata Stored]
        MINT_ICP[Mint on ICP]
    end

    subgraph Distribution
        KYC_CHECK[KYC Verified]
        CHAIN_SEL[Chain Selected]
        MINT_EXT[Mint on External Chain]
    end

    subgraph Operations
        TRANSFER[Transfers]
        YIELD[Yield Payments]
        REDEEM[Redemption]
    end

    BOND --> META --> MINT_ICP
    MINT_ICP --> KYC_CHECK --> CHAIN_SEL --> MINT_EXT
    MINT_EXT --> TRANSFER
    MINT_EXT --> YIELD
    MINT_EXT --> REDEEM

# Security Model

All cross-chain operations require multiple security checks:

flowchart TB
    REQ[Operation Request] --> V1[KYC Verification]
    V1 --> V2[Balance Check]
    V2 --> V3[Compliance Rules]
    V3 --> SIGN[Threshold Signature]
    SIGN --> EXEC[Execute on Target Chain]
    EXEC --> CONFIRM[Confirmation]
    CONFIRM --> UPDATE[Update Master Ledger]

Key security properties:

Threshold Signatures: No single node can sign transactions
Consensus Required: ICP subnet consensus before any cross-chain action
Immutable Audit Log: All operations recorded on master ledger
KYC Enforcement: Protocol-level, not bypassable

# Network Topology

flowchart TB
    subgraph ICP_SUBNET["ICP Subnet"]
        N1[Node 1]
        N2[Node 2]
        N3[Node 3]
        N4[Node N...]
    end

    subgraph CANISTERS["Tortuga Canisters"]
        C1[Master Ledger]
        C2[KYC Registry]
        C3[Chain Fusion]
    end

    N1 & N2 & N3 & N4 --> CANISTERS

    C3 --> ETH[Ethereum]
    C3 --> BASE[Base]
    C3 --> SOL[Solana]
    C3 --> OSMO[Osmosis]

Canisters run on a dedicated ICP subnet with nodes distributed globally for fault tolerance and decentralization.