Native Messaging Systems

Introduction to Native Messaging Systems

Every Ethereum Layer 2 (L2), Layer 3 (L3), or App Chain has its own native messaging system. This system allows for secure communication between the layer in question and Ethereum mainnet (Layer 1). Storage Proofs leverage these native messaging systems to enhance the efficiency and security of cross-chain data verification.

How Storage Proofs Utilize Native Messaging

Instead of sending large amounts of data between chains, Storage Proofs use these native messaging systems to send compact, critical pieces of information:

1. Block Hashes: A cryptographic fingerprint of a block's content.

2. Root of Historical Block Hash Accumulator: A single hash that represents a large set of historical block hashes.

The Significance of This Approach

Efficiency

By sending only block hashes or accumulator roots, the amount of data transmitted between chains is drastically reduced. This leads to:

• Lower gas costs

• Faster cross-chain communication

• Reduced congestion on both the source and destination chains

Security

Using the native messaging system means relying on security mechanisms that are already in place and trusted. This approach:

• Doesn't introduce new trust assumptions

• Leverages the existing security model of the L2/L3/App Chain

Trustlessness

Users of an L2, L3, or App Chain already trust its native messaging system for critical operations. By using this same system for Storage Proofs, the trustless nature of the blockchain ecosystem is maintained. Users don't need to place trust in any additional third parties or systems.

Verifiability

Once the block hash or accumulator root is received on the destination chain:

• It can be used to verify any data from the source chain

• Proofs can be generated and verified against this trusted reference point

Scalability

This approach scales well as the amount of data or the frequency of cross-chain communication increases. The size of the message sent through the native messaging system remains constant, regardless of the amount of data being proved.

Practical Example

Consider a scenario where a smart contract on Optimism (an L2) needs to verify data from Ethereum mainnet:

1. The block hash or accumulator root from Ethereum is sent to Optimism using Optimism's native messaging system.

2. This information is received and stored on Optimism.

3. When a smart contract on Optimism needs to verify Ethereum data:

   • The relevant data and a proof are submitted to the contract.

   • The contract can verify this proof against the trusted block hash or accumulator root.

   • If the verification succeeds, the contract can trust and use the Ethereum data.

Conclusion

By leveraging native messaging systems, Storage Proofs provide a secure, efficient, and scalable method for cross-chain data verification. This approach maintains the trustless nature of blockchain interactions while enabling powerful cross-chain functionalities.