Kroma

Contains configuration parameters such as the SequencerA party responsible for ordering and executing transactions on the rollup. The sequencer verifies transactions, compresses the data into a block, and submits the data related to it to enable state reconstruction to Ethereum L1 as a single transaction. The data can be either transaction data or state diffs. address, gas limitThe maximum amount of gas a transaction or block may consume. on this chain and the unsafe blockAn ordered list of transactions and chain-related metadata that gets bundled together and published to the L1/DA layer. Nodes execute the transactions contained within blocks to change the rollup chain’s state. Protocol rules dictate what constitutes a valid block, and invalid blocks are skipped over. signer address.

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners
  • batcherHash: EOA 1
  • owner: Timelock; ultimately SecurityCouncilTokenOwners

Sends messages from host chain to this chain, and relays messages back onto host chain. In the event that a message sent from host chain to this chain is rejected for exceeding this chain’s epoch gas limitThe maximum amount of gas a transaction or block may consume., it can be resubmitted via this contract’s replay function.

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners

Used to bridgeA message-passing protocol between two blockchains. At its most basic, a token bridge consists of a smart contract which can escrow funds on one side of the bridge, and instruct the release or minting of corresponding assets on the other side, but bridges could also support arbitrary messages. How these instructions are validated is a critical factor in assessing the trust assumptions of a bridge. ERC-721 tokens from host chain to this chain.

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners

The main entry point to deposit ERC20 tokens from host chain to this chain.

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners

The L2OutputOracle contract contains a list of proposed state rootsA cryptographic hash succinctly representing a state using a Merkle tree. which Proposers assert to be a result of blockAn ordered list of transactions and chain-related metadata that gets bundled together and published to the L1/DA layer. Nodes execute the transactions contained within blocks to change the rollup chain’s state. Protocol rules dictate what constitutes a valid block, and invalid blocks are skipped over. execution. Anyone can participate as a ProposerIn the context of L2s, the actor that proposes a claimed state root on L1. The term is also used in the context of Ethereum to refer to the actor that proposes a new block. by depositing in the ValidatorPool. A root can be proposed every 1800 blocks (2s block time).

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners

A standard timelock with access control. The current minimum delay is 0s.

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners
  • canceller: UpgradeGovernor; ultimately SecurityCouncilTokenOwners
  • executor: UpgradeGovernor; ultimately SecurityCouncilTokenOwners
  • proposerIn the context of L2s, the actor that proposes a claimed state root on L1. The term is also used in the context of Ethereum to refer to the actor that proposes a new block.: UpgradeGovernor; ultimately SecurityCouncilTokenOwners
  • timelockAdmin: Timelock, UpgradeGovernor; ultimately SecurityCouncilTokenOwners

Manages the set of Proposers (ValidatorsIn the context of L2s, a Validator is an actor that validates the correctness of state transitions. For optimistic rollups this corresponds to challengers, and for ZK rollups this corresponds to the onchain verifier in Kroma) and selects the next proposerIn the context of L2s, the actor that proposes a claimed state root on L1. The term is also used in the context of Ethereum to refer to the actor that proposes a new block. with the window to submit the output root within 30m, after which anyone can propose for them. It is also the entry point for other contracts, such as the L2OutputOracle and the Colosseum, which distribute output rewards and slash challenge losers. It makes successive calls to the AssetManager to apply changes to the proposers’ assets.

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners

This is a fork of the standard OP stack OptimismPortal contract, the main entry point to deposit funds from L1Layer 1 (L1) is a blockchain that is self-reliant on its validator set for its security and consensus properties. Ethereum is an example of a layer 1. Blockchains started receiving the moniker of layer 1 once layer 2 became a meaningful area of development. to L2Layer 2 (L2) is a category of technical solutions aimed to scale the base layer in a trust minimized way. This category includes solutions like rollups as well as state channels and plasma. Other solutions are able to scale further, but with the introduction of additional trust assumptions, which are therefore not trust minimized. Sometimes the term Layer 2 is used to refer to include these solutions too, like validiums and optimiums, but to distinguish between trust minimized and non trust minimized solutions they are often referred to as "light" L2s, opposed to "strong" L2s like rollups.. It also allows to prove and finalize withdrawals.

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners
  • guardian: KromaSecurityCouncil

Merkle Trie contract used to prove withdrawals that were initiated in the legacy system, deprecated for new withdrawals and succeeded by a merkle treeA hash-based data structure in which each leaf node is a hash of a block of data, and each non-leaf node is a hash of its children. The root of the tree is a cryptographic fingerprint of the entire data structure. Merkle trees (Merkle Patricia Tries) are used in Ethereum to efficiently store key-value pairs. library in the KromaPortal.

• Roles:
  • owner: Timelock

ZK verifierAn entity in a ZK-Rollup, often a smart contract, that verifies zero-knowledge proofs submitted by a prover. used to verify the last step of a legacy zkEVM proof, which corresponds to a blockAn ordered list of transactions and chain-related metadata that gets bundled together and published to the L1/DA layer. Nodes execute the transactions contained within blocks to change the rollup chain’s state. Protocol rules dictate what constitutes a valid block, and invalid blocks are skipped over..

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners

Contract used to challenge state rootsA cryptographic hash succinctly representing a state using a Merkle tree. and prove fraud. If successful, the wrong state root in the L2OutputOracle is replaced.

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners
  • security_council: KromaSecurityCouncil

• Roles:
  • admin: Timelock; ultimately SecurityCouncilTokenOwners

Manages the delegation and undelegation of KRO tokens and Kroma Guardian House (KGH) NFTs for Proposers (Kroma ValidatorsIn the context of L2s, a Validator is an actor that validates the correctness of state transitions. For optimistic rollups this corresponds to challengers, and for ZK rollups this corresponds to the onchain verifier) and distributes rewards.

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners

A governance proxy contract using token voting with SecurityCouncilTokenOwners as identification of actors allowed to vote/sign a proposal which is passed to the Timelock afterwards.

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners
  • token: SecurityCouncilTokenOwners

Contract used to manage the Proposers. Anyone can submit a deposit and bond to a state rootA cryptographic hash succinctly representing a state using a Merkle tree., or create a challenge. It also manages the ProposerIn the context of L2s, the actor that proposes a claimed state root on L1. The term is also used in the context of Ethereum to refer to the actor that proposes a new block. rotation for each submittable blockAn ordered list of transactions and chain-related metadata that gets bundled together and published to the L1/DA layer. Nodes execute the transactions contained within blocks to change the rollup chain’s state. Protocol rules dictate what constitutes a valid block, and invalid blocks are skipped over. using a random selection. If the selected proposer fails to publish a root within 30m then the submission becomes open to everyone.

• Roles:
  • admin: ProxyAdmin; ultimately SecurityCouncilTokenOwners
  • security_council: KromaSecurityCouncil

VerifierAn entity in a ZK-Rollup, often a smart contract, that verifies zero-knowledge proofs submitted by a prover. contract for SP1 proofs (v5.0.0).

This contract is the router for zk proof verification. It stores the mapping between identifiers and the address of onchain verifierAn entity in a ZK-Rollup, often a smart contract, that verifies zero-knowledge proofs submitted by a prover. contracts, routing each identifier to the corresponding verifier contract.

• Roles:
  • owner: SP1VerifierGatewayMultisig

VerifierAn entity in a ZK-Rollup, often a smart contract, that verifies zero-knowledge proofs submitted by a prover. contract for SP1 proofs (v6.0.0).

VerifierAn entity in a ZK-Rollup, often a smart contract, that verifies zero-knowledge proofs submitted by a prover. contract for SP1 proofs (v6.1.0).