Knot on DuskEVM
Status: deployed on DuskEVM testnet, testnet only, not audited yet. The address is on Deployments (knot-evm-root).
A group on Dusk can also be checked from a Solidity contract on DuskEVM. The EVM contract, KnotEvmRoot, keeps a short fingerprint of each group: who the members are, the threshold, and a counter that goes up every time the group changes. It holds no keys and no funds. Your EVM contract asks it one question: did enough current members of this group sign this action?
How a group gets there
- First member set. Enough of the group's members sign the member set on Dusk. The Knot registry checks those signatures, then sends the member set once through DuskEVM's cross-domain messenger to
KnotEvmRoot.KnotEvmRootonly accepts it from the registry it was deployed for. - Later changes. After that, the group changes its own members on the EVM side with
rotate, signed by enough current members. Each change raises the counter, and every signature made before it stops working.
On testnet we ran this end to end on 2026-10-28: a 2-of-3 group was sent from Dusk, arrived on DuskEVM through the messenger, and a checkAction signed by two of its members went through.
Asking it from your contract
| Call | What it does |
|---|---|
checkAction(accountId, actionDigest, quorum) | Checks the signatures against the group's current members and threshold, and marks that action as used. The same signed action can't be used twice |
isBootstrapped, membersRoot, threshold, rotationNonce | Read the group's current state |
isConsumed(accountId, actionDigest) | Whether an action was already used |
actionMessage, rotationMessage | The exact bytes members sign |
The signed message includes the calling contract's address and the current counter, so a signature made for one contract, or before a change, can't be reused somewhere else.
Doing it with the Lab's tool
knot-tool evm does both steps with members' own identity stores. Each member signs into one shared file, which holds only public keys and signatures:
bash
# each member, from their own store
knot-tool --store <store> evm bootstrap-sign --account <id> --receiver <KnotEvmRoot> --signer <name> --file bootstrap.json --confirm
# anyone, once enough members signed (pays DuskDS gas)
knot-tool evm bootstrap-submit --file bootstrap.json --confirm
# each member signs an action for a given consumer contract
knot-tool --store <store> evm action-sign --account <id> --root <KnotEvmRoot> --evm-chain 745 \
--rotation-nonce <n> --consumer <address> --digest <32 bytes> --signer <name> --file action.json --confirm
# prints the checkAction call for the consumer to send
knot-tool evm action-args --file action.jsonEvery command shows a preview and a fingerprint first, and only signs or sends with --confirm.
Signatures
Members use the same BLS keys as on Dusk. The contract checks them with the BLS12-381 precompiles Ethereum added in Pectra (EIP-2537), which DuskEVM supports. BLS on its own is nothing unusual on EVM chains; what this adds is that the group is the same one that exists on Dusk.
What isn't there yet
- A group changed on Dusk after it was sent is not updated on DuskEVM automatically. It has to
rotatethere too. - Not audited yet.
Source: evm/ in the Knot repo.