System Overview

c-Lightning Validating Signer Demo

VLS Integration Modes

VLS components can be integrated with C-Lightning (CLN) or the Lightning Development Kit (LDK).

NOTE - All combinations are not depicted, for example LDK:SERIAL is a valid mode.

System Overview

The Lightning Node makes requests to the Remote Signer to generate signatures for lightning operations.

Detail:

• The Remote Signer consists of two processing entities.

  • The Front End has reasonable resources and is connected to the network.

  • The Secure Element has limited resources and is hardened against physical attacks.

• Validation of a request signing operation may require proof that UTXOs are currently unspent. Requests are made to a (set) of UTXO set Oracles which provide proofs of inclusion.

• A design requirement is that an exploit which compromises the Front End but not the Secure Element cannot violate signing policies.

Multi-Party Signing

Additional protection may be obtained by using multi-party computation to generate the signatures.

The Lightning Node makes requests to any one of the Remote Signers. The Remote Signer Front End initiates the multi-party signing operation and relays the resulting signature(s) back to the Lightning Node.

Protocol-Level Signing Flow

Want to see how VLS fits into the Lightning lifecycle?

Check out our Sequence Diagrams for:

• Channel Establishment
• Normal Operation
• Lightning Transaction Signing Details