Security Assumptions

• Ethereum MRV already exists, is fixed supply, and cannot be minted by the bridge.
• The bridge never introduces wMRV.
• The Ethereum vault must never release more MRV than it holds.
• LP principal supplies bridge liquidity in V1 and can be constrained by utilization.
• Relayers wait configurable Ethereum and Minerva finality confirmations.
• Message replay protection includes both chain IDs, both assets, sender, recipient, amount, fee, nonce, deadline, source transaction hash, and domain separator.

Releases are verified on-chain on both sides

• A release on either chain takes the full bridge message and a guardian attestation. The vault hashes the message, checks chains and assets, requires the deadline not to have passed, verifies the guardian threshold, and records execution in the registry.
• A relayer may submit a release but cannot authorize one. The relayer key alone moves nothing.

Cancellation needs evidence, never a timer

• A lock (Minerva side) or deposit (Ethereum side) is refundable only after a guardian-attested cancellation. Guardians sign keccak256(abi.encode(CANCEL_DOMAIN, messageHash, destinationChainId)) only once the destination chain has recorded the message as Expired.
• The destination records expiry (markInboundExpired) only after deadline + expiryMargin, and refuses releases once the deadline has passed. Expired and Released are therefore mutually exclusive on the destination chain regardless of clock skew between chains.
• An executed transfer is settled on its source chain (confirmOutboundExecuted, confirmDepositExecuted) and can never be cancelled afterwards; a cancelled transfer can never be confirmed. Double payout, where a destination release succeeds and the source refunds the same transfer, is impossible by construction.
• Deposits on Ethereum are escrow until confirmed. Only settled (executed) deposits can be swept into LP inventory.

Guardians

• Guardian threshold signatures are required for releases and cancellations on both chains.
• Minerva-side guardian keys in threshold mode are ECDSA keys checked by MinervaBridgeGuardianVerifier; in devnet single-guardian mode the executor must be the guardian's PQ account. Replacing ECDSA guardian verification on Minerva with ML-DSA attestations is a planned upgrade; until then the bridge's guardian set is a classical boundary on both chains.
• Ethereum-side admin controls use a multisig before production. A PQ-controlled Minerva account does not make an Ethereum contract post-quantum.

Rewards

• ETH rewards are time-weighted: each epoch's funded ETH is split by share-seconds. Rewards are separately funded and never form part of bridge principal or release capacity.

Operations

• Relayers must treat Minerva reorgs as first-class risk: unfinalized observations are not executable, and reorged observations are invalidated instead of retried blindly.
• The relayer is obliged to settle executed transfers on the source chain and to record expiries and cancellations; anyone can perform these steps if it does not.