Inter-Chain Bridges

Cross-group communication within dregg now uses multi-group participation (dregg-node run --groups) with interest-based dissemination and cryptographic cross-references. The old dregg-node bridge command has been removed. This page documents inter-chain bridges to external networks (EVM, Mina, Midnight).

EVM Bridge (Base Sepolia)

The EVM bridge wraps dregg STARK proofs in Groth16 via SP1 for on-chain verification (~200K gas). Operators run the bridge relay to facilitate deposits and withdrawals.

# Run the EVM bridge relay
dregg-node bridge-evm \
  --data-dir ~/.dregg \
  --rpc-url https://sepolia.base.org \
  --bridge-contract 0x... \
  --private-key-file ./keys/bridge-operator.key \
  --port 8422

# The relay watches for on-chain deposit events and submits
# corresponding note commitments to the federation.

Component	Description
SP1 Verifier Gateway	Succinct's deployed contract verifying Groth16 proofs
DreggBridge contract	State commitment registry + deposit/withdraw logic
VK Registry	Governance-managed verification key updates (multisig)
Incremental Merkle tree	O(log n) deposit insertions on-chain

Mina Bridge

The Mina bridge uses native Pickles recursion. dregg STARK proofs are wrapped in Kimchi circuits over Pasta curves, producing Pickles recursive proofs that Mina validators verify natively. No relay operator is required for proof verification -- the proofs are self-contained.

# Generate a Mina-compatible proof
dregg proof generate --backend kimchi --turn $TURN_HASH
dregg proof wrap-pickles --input $KIMCHI_PROOF --output mina-proof.bin

# Submit to a Mina zkApp (requires o1js tooling)
# The proof is natively verifiable by Mina's consensus

Midnight/Cardano Bridge

The Midnight bridge operates at Level 1.5: optimistic acceptance with a dispute window. Operators run an attestation relay.

# Run the Midnight attestation relay
dregg-node bridge-midnight \
  --data-dir ~/.dregg \
  --midnight-endpoint wss://midnight-node.example.com \
  --attestation-interval 100  # attest every 100 blocks
  --bond-amount 50000

Bridge Security Model

EVM (Level 2): Trust assumption is SP1/Groth16 soundness. No trusted relay.
Mina (Level 2): Trust assumption is Pickles/IPA soundness. No trusted relay.
Midnight (Level 1.5): Trust assumption is that at least one honest party will challenge invalid submissions within the dispute window.

All bridges use proof translation, not consensus bridging. There is no multisig, no threshold committee, no trusted set of bridge operators that could collude. The math is the bridge.