dlt_interop/Multisig Relay.html at main · bparth24/dlt_interop · GitHub

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<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Multisig Relay</title>
    <script type="module">
      import mermaid from "https://cdn.jsdelivr.net/npm/mermaid@10/dist/mermaid.esm.min.mjs";
      mermaid.initialize({ startOnLoad: true });
    </script>
  </head>
  <body>
    <h1>3.1 Multisig Relay</h1>

    <h2>Overview Mechanism</h2>

    <p>
      This approach uses multiple signatures to verify and authenticate
      messages. Here’s how it works:
    </p>

    <ol>
      <li>
        <strong>Message Signing:</strong>
        <ul>
          <li>
            A message is created on the source chain and signed by several
            independent relay nodes, each with a unique public key. These relay
            nodes are part of a whitelist maintained by the target chain's smart
            contract.
          </li>
        </ul>
      </li>
      <li>
        <strong>Signature Aggregation:</strong>
        <ul>
          <li>
            The signatures from these nodes are aggregated into a single
            signature payload. This payload, along with the original message, is
            sent from the source chain to the target chain.
          </li>
        </ul>
      </li>
      <li>
        <strong>Verification:</strong>
        <ul>
          <li>
            On the target chain, the smart contract checks the aggregated
            signature against the whitelist to ensure it includes valid
            signatures from the required number of trusted relayers. If the
            verification is successful, the message is deemed authentic and
            processed.
          </li>
        </ul>
      </li>
    </ol>

    <h2>Security Features Section</h2>

    <ul>
      <li>
        <strong>Decentralization:</strong> Multiple validators are involved in
        signing the message, reducing the risk of a single point of failure.
      </li>
      <li>
        <strong>Integrity Assurance:</strong> By requiring a threshold number of
        signatures, multisig relay ensures that only messages with broad
        consensus are trusted.
      </li>
      <li>
        <strong>Availability:</strong> The approach provides higher availability
        and robustness against attacks, as it relies on multiple independent
        nodes.
      </li>
    </ul>

    <h2>Analogy</h2>

    <p>
      Think of it like a secure bank transaction that requires approval from
      multiple managers before it can be processed. Each manager signs off on
      the transaction, and only if all signatures are valid does the transaction
      go through.
    </p>

    <hr />

    <p>
      <strong
        >Here below is the content as is from the spec just added sections for
        better readability</strong
      >
    </p>

    <hr />

    <h2>Multisig Relay</h2>

    <p>
      Multisig relay is a mechanism that leverages multi-signature consensus for
      relaying messages across blockchains. In this approach, the message
      originating from a source chain is cryptographically signed by multiple
      independent relay nodes.
    </p>

    <h2>Mechanism</h2>

    <p>
      <strong>Message Signing:</strong> These relay nodes or validators have
      public key signatures that are registered and verified against a whitelist
      of trusted nodes maintained on the target chain's smart contract.
    </p>

    <p>
      <strong>Signature Aggregation:</strong> The relay nodes' signatures on the
      message are aggregated and attached to the communication payload sent from
      the source chain to the smart contract on the target chain.
    </p>

    <p>
      <strong>Verification:</strong> The target chain's smart contract first
      verifies that the aggregate signature comprises valid signatures from a
      threshold number of trusted relayers according to the whitelist. This
      blockchain-based consensus check establishes multiple attestations of the
      message's authenticity and integrity. If the multi-signature passes the
      policy set on the target chain, the message is deemed to have originated
      genuinely from the source system and can be processed and trusted
      accordingly by the target chain.
    </p>

    <h2>Security Features</h2>

    <p>
      By decentralizing the act of relaying through multiple participating
      validators and embedding multi-signature thresholds on target chains,
      multisig message relay aims to provide stronger security, availability,
      and integrity assurances for crosschain messaging.
    </p>

    <h2>Example</h2>

    <p>
      Think of it like a secure bank transaction that requires approval from
      multiple managers before it can be processed. Each manager signs off on
      the transaction, and only if all signatures are valid does the transaction
      go through.
    </p>

    <hr />

    <h2>Sequence Diagram</h2>
    <img src="MultisigRelay.svg" alt="Multisig Relay Diagram" />

    <h2>Explanation</h2>

    <ul>
      <li>
        <strong>SourceChain:</strong> Represents the blockchain where the
        message originates.
      </li>
      <li>
        <strong>RelayNode1</strong> and <strong>RelayNode2:</strong> Independent
        relay nodes that sign the message.
      </li>
      <li>
        <strong>TargetChain:</strong> Represents the blockchain where the
        message is received and verified.
      </li>
    </ul>

    <p><strong>Flow:</strong></p>

    <ol>
      <li>
        The <strong>SourceChain</strong> sends the message to
        <strong>RelayNode1</strong> and <strong>RelayNode2</strong> for signing.
      </li>
      <li>
        Each relay node signs the message and sends its signature back to the
        <strong>SourceChain</strong>.
      </li>
      <li>
        The <strong>SourceChain</strong> aggregates the signatures from the
        relay nodes.
      </li>
      <li>
        The aggregated message and signatures are sent from the
        <strong>SourceChain</strong> to the <strong>TargetChain</strong>.
      </li>
      <li>
        The <strong>TargetChain</strong> verifies the aggregated signatures
        against a whitelist and checks if the threshold is met.
      </li>
      <li>
        If verification is successful, the
        <strong>TargetChain</strong> processes the message and confirms its
        authenticity.
      </li>
    </ol>
  </body>
</html>