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Params

This document describes and advises configuration of the Peggy module's parameters. The default parameters can be found in the genesis.go of the peggy module.

type Params struct {
    PeggyId                       string                                 
    ContractSourceHash            string                                 
    BridgeEthereumAddress         string                                 
    BridgeChainId                 uint64                                 
    SignedValsetsWindow           uint64                                 
    SignedBatchesWindow           uint64                                 
    SignedClaimsWindow            uint64                                 
    TargetBatchTimeout            uint64                                 
    AverageBlockTime              uint64                                 
    AverageEthereumBlockTime      uint64                                 
    SlashFractionValset           sdk.Dec 
    SlashFractionBatch            sdk.Dec 
    SlashFractionClaim            sdk.Dec 
    SlashFractionConflictingClaim sdk.Dec 
    UnbondSlashingValsetsWindow   uint64  
    SlashFractionBadEthSignature  sdk.Dec 
    CosmosCoinDenom               string  
    CosmosCoinErc20Contract       string  
    ClaimSlashingEnabled          bool    
    BridgeContractStartHeight     uint64  
    ValsetReward                  types.Coin
}

peggy_id​

A random 32 byte value to prevent signature reuse, for example if the Injective Chain validators decided to use the same Ethereum keys for another chain also running Peggy we would not want it to be possible to play a deposit from chain A back on chain B's Peggy. This value IS USED ON ETHEREUM so it must be set in your genesis.json before launch and not changed after deploying Peggy. Changing this value after deploying Peggy will result in the bridge being non-functional. To recover just set it back to the original value the contract was deployed with.

contract_source_hash​

The code hash of a known good version of the Peggy contract solidity code. This can be used to verify the correct version of the contract has been deployed. This is a reference value for governance action only it is never read by any Peggy code

bridge_ethereum_address​

is address of the bridge contract on the Ethereum side, this is a reference value for governance only and is not actually used by any Peggy module code.

The Ethereum bridge relayer use this value to interact with Peggy contract for querying events and submitting valset/batches to Peggy contract.

bridge_chain_id​

The bridge chain ID is the unique identifier of the Ethereum chain. This is a reference value only and is not actually used by any Peggy code

These reference values may be used by future Peggy client implementations to allow for consistency checks.

Signing windows​

  • signed_valsets_window
  • signed_batches_window
  • signed_claims_window

These values represent the time in blocks that a validator has to submit a signature for a batch or valset, or to submit a claim for a particular attestation nonce.

In the case of attestations this clock starts when the attestation is created, but only allows for slashing once the event has passed. Note that that claims slashing is not currently enabled see slashing spec

target_batch_timeout​

This is the 'target' value for when batches time out, this is a target because Ethereum is a probabilistic chain and you can't say for sure what the block frequency is ahead of time.

Ethereum timing​

  • average_block_time
  • average_ethereum_block_time

These values are the average Injective Chain block time and Ethereum block time respectively and they are used to compute what the target batch timeout is. It is important that governance updates these in case of any major, prolonged change in the time it takes to produce a block

Slash fractions​

  • slash_fraction_valset
  • slash_fraction_batch
  • slash_fraction_claim
  • slash_fraction_conflicting_claim

The slashing fractions for the various peggy related slashing conditions. The first three refer to not submitting a particular message, the third for failing to submit a claim and the last for submitting a different claim than other validators.

Note that claim slashing is currently disabled as outlined in the slashing spec

valset_reward​

Valset reward is the reward amount paid to a relayer when they relay a valset to the Peggy contract on Ethereum.