Layer 0 — Bitcoin & OmniCore

Role: The Immutable Motherboard

Bitcoin serves as the Layer-0 "Motherboard" for Dong Chain. It provides:

• Censorship-resistant finality: Assets recorded on Bitcoin inherit the world's largest PoW security
• Immutable RWA registry: All asset issuances are permanently recorded via OmniCore OP_RETURN
• Trust anchor for bridges: BitVM2 uses Bitcoin as the final dispute resolution layer

Bitcoin Node Setup

Required Configuration (bitcoin.conf)

# MANDATORY: Full transaction index — OmniCore will refuse to start without this
txindex=1

# RPC access
rpcuser=dongchain
rpcpassword=<strong-random-password>
rpcport=8332
server=1

# Performance tuning
dbcache=4096          # 4GB DB cache for faster sync
maxmempool=512        # 512MB mempool

# Indexing
addressindex=1        # Required for address balance queries
timestampindex=1      # Required for timestamp queries
spentindex=1          # Required for spent output queries

Warning: If txindex=1 is added after the node is already synced, a full re-index is required. This can take 12-24 hours. Plan accordingly.

Initial Sync Timeline (Reference Hardware)

Hardware	Initial Bitcoin Sync	OmniCore Parse
8-core, 32GB RAM, HDD	48-72 hours	3-5 hours
16-core, 64GB RAM, NVMe	12-24 hours	60-90 minutes
32-core, 128GB RAM, NVMe RAID	4-8 hours	30-45 minutes

Health Check Commands

# Verify node is synced
bitcoin-cli getblockchaininfo | jq .verificationprogress

# Verify txindex is active
bitcoin-cli getindexinfo

# Expected output:
# {
#   "txindex": {
#     "synced": true,
#     "best_block_height": <current_height>
#   }
# }

OmniCore Integration

What is OmniCore?

OmniCore is a Bitcoin Core fork that adds the Omni Layer meta-protocol. It parses special Bitcoin transactions to maintain a parallel asset registry without changing Bitcoin's consensus rules.

Think of it as: HTTP running on TCP/IP — OmniCore adds asset semantics on top of Bitcoin's transport layer.

Encoding Mechanisms

Layer B (Multisig Encoding)

Embeds up to 66 bytes per public key slot into multisig outputs:

OP_1 <data_pubkey_1> <data_pubkey_2> <signing_pubkey> OP_3 OP_CHECKMULTISIG

Layer C (OP_RETURN Encoding — Preferred)

Embeds up to 80 bytes into an unspendable output:

OP_RETURN <0x6f6d6e69> <asset_type: 2 bytes> <property_id: 4 bytes> <amount: 8 bytes> ...

Where 0x6f6d6e69 is the Omni protocol magic bytes ("omni" in ASCII).

Asset Issuance

Create a Fixed-Supply RWA Token

omnicore-cli omni_sendissuancefixed \
  "bc1q..." \           # From address (issuer)
  1 \                   # Ecosystem: 1=mainnet
  2 \                   # Type: 2=divisible (like ERC-20), 1=indivisible (like NFT)
  0 \                   # Previous ID: 0 for new token
  "Real Estate" \       # Category
  "Commercial" \        # Subcategory
  "Hanoi Office Tower" \# Name
  "https://issuer.com/token-info" \  # URL
  "Tokenized ownership of 100 Nguyen Hue, Hanoi" \  # Data
  "1000000"             # Total supply (1,000,000 tokens)

Response:

{
  "txid": "abc123...",
  "propertyid": 42
}

Query Asset State

# Get all assets issued by an address
omnicore-cli omni_listproperties

# Get specific property info
omnicore-cli omni_getproperty 42

# Get balance
omnicore-cli omni_getbalance "bc1q..." 42

State Synchronization to Dong Chain

The OmniCore state must be mirrored to the Dong Chain runtime. The bridge module:

1. Subscribes to omni_listtransactions for new Omni Layer events
2. On each Bitcoin block, queries changed balances
3. Produces proofs of OmniCore state for the BitVM2 oracle

// Pseudocode: OmniCore state listener
async fn omnicore_listener(rpc: &OmniRpcClient) {
    let mut last_height = get_last_processed_height();

    loop {
        let current_height = rpc.get_block_count().await?;

        for height in last_height..current_height {
            let block = rpc.get_block_hash(height).await?;
            let txs = rpc.omni_list_transactions_for_block(block).await?;

            for tx in txs {
                if tx.is_peg_in_lock() {
                    emit_peg_in_event(tx);
                }
            }
        }

        last_height = current_height;
        sleep(Duration::from_secs(30)).await;
    }
}

Storage Requirements

Data	Size (2026)	Growth
Bitcoin blockchain	~700 GB	~50 GB/year
Bitcoin indexes (txindex, etc.)	~100 GB	~7 GB/year
OmniCore state DB	~10 GB	~1 GB/year
Total	~810 GB	~58 GB/year

Recommendation: Use a dedicated 2TB NVMe SSD for Layer-0 data with automated backup.

Limitations of Layer 0

OmniCore is intentionally limited — it is a "Depository of Truth" only:

Can Do	Cannot Do
Issue fungible tokens	Execute conditional logic
Transfer token ownership	Run AMMs or lending protocols
Record immutable metadata	Process cross-chain messages
Maintain audit trail	Interact with other chains

All programmable logic must happen on Dong Chain's RISC-V layer after bridging.

Related Docs

• BitVM2 Bridge — How assets cross from Layer 0 to Dong Chain
• Depository Contract — Cross-chain liquidity protocol