Summary Value Secured Risk summary Risk analysis Data availability State validation Operator Withdrawals Smart contracts

Polygon Hermez

This project is archived and no longer maintained.

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About

Hermez is an open-source ZK Rollup that aims to be optimized for secure, low-cost and usable token transfers on the wings of Ethereum.

Total Value SecuredTVS

$313.98 K8.48%

Past day UOPSDaily UOPS

No data

Type

ZK Rollup

Purpose

Payments

Tokens breakdown

Value secured breakdown

Sequencer failureState validationData availabilityExit windowProposer failure

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About

Hermez is an open-source ZK Rollup that aims to be optimized for secure, low-cost and usable token transfers on the wings of Ethereum.

Value Secured

2021 Mar 24 — 2025 Jul 18

View TVS breakdown

Total value securedTotal

$313.98 K8.48%

Canonically BridgedCanonically Bridged ValueCanonical

$313.98 K8.48%

Natively MintedNatively Minted TokensNative

$0.000.00%

Externally BridgedExternally Bridged ValueExternal

$0.000.00%

View TVS breakdown

Risk summary

Hermez and Polygon have recently merged. Hermez and Polygon Hermez are two names for the same rollup.

Funds can be stolen if

the operators trigger a false alarm during withdrawal (CRITICAL),
a contract receives a malicious code upgrade. There is a 7 days delay on code upgrades.

Funds can be frozen if

the operator refuses to include their transactions and users lack resources to propose blocks themselves.

Risk analysis

Hermez and Polygon have recently merged. Hermez and Polygon Hermez are two names for the same rollup.

Sequencer failureState validationData availabilityExit windowProposer failure

Sequencer failure

Force via L1

Users can force the sequencer to include a withdrawal transaction by submitting a request through L1. If the sequencer censors or is down for , users can use the exit hatch to withdraw their funds.

State validation

ZK proofs (SN)

SNARKs are zero knowledge proofs that ensure state correctness, but require trusted setup.

Data availability

Onchain

All of the data needed for proof construction is published on Ethereum L1.

Exit window

Users have 7d to exit funds in case of an unwanted regular upgrade. There is a 7d delay before a regular upgrade is applied, and withdrawals can take up to 0s to be processed.

Proposer failure

Self propose

If the Proposer fails, users can leverage the source available prover to submit proofs to the L1 bridge.

Data availability

All data required for proofs is published onchain

All the data that is used to construct the system state is published onchain in the form of cheap calldata. This ensures that it will always be available when needed.

Data Availability - Hermez documentation

State validation

Validity proofs

Each update to the system state must be accompanied by a ZK proof that ensures that the new state was derived by correctly applying a series of valid user transactions to the previous state. These proofs are then verified on Ethereum by a smart contract.

ZK proofs - Hermez documentation

Operator

There is no central operator

The system runs an auction in which anyone can bid to become the operator for a set number of blocks. The operator will be able to propose blocks and collect fees during this window. Hermez will also run an operator known as boot coordinator that will propose blocks in case no one bids in the auction. This operator can be removed by the governance.

Users can force any transaction

Because the block production is open to anyone if users experience censorship from the operator they can propose their own blocks which would include their transactions.

Funds can be frozen if the operator refuses to include their transactions and users lack resources to propose blocks themselves.

Can coordinators censor transactions? - Hermez documentation

Withdrawals

Regular exit

The user initiates the withdrawal by submitting a regular transaction on this chain. When the block containing that transaction is settled the funds become available for withdrawal on L1.ZK proofs are required to settle blocks. Finally the user submits an L1 transaction to claim the funds. This operation cannot be performed if the withdrawal exceeds certain threshold.

Withdrawing Funds from Hermez - Hermez documentation

Forced withdraw

The user submits the withdrawal request on L1. This forces the operators to pick up the request before other L2 transactions. A block still needs to be proved, the user still submits a merkle proof, and the funds threshold still cannot be exceeded.

Force Exit - Hermez documentation

Delayed withdraw

When the user does a regular or forced withdraw and their funds exceed a certain threshold a timer activates. After a specified time has passed and the emergency mode has not been activated the funds can be withdrawn.

Withdrawal Delayer Mechanism - Hermez documentation

Emergency mode

When the user does a regular or forced withdraw and their funds exceed a certain threshold a timer activates. The operators can now trigger emergency mode and transfer the user’s funds to the governance.