Verifying eth_call Results with Cryptographic Proofs for L1s and L2s
As the adoption of decentralized applications (dApps) on the Ethereum network continues to grow, ensuring the reliability and integrity of static call requests (eth_call) is becoming increasingly important. Currently, the returned data from these calls can be as trustworthy as the node or service providing it, which may not always be the case.
In this article, we will explore how cryptographic proofs can be used to verify the results of eth_call requests on both Layer 1 (L1) and Layer 2 (L2) networks.
Understanding Ethereum’s L1 and L2 Networks
Before diving into the world of cryptography, it’s essential to understand the two primary layers that make up the Ethereum network:
- Layer 1 (L1): This refers to the underlying blockchain, which is responsible for executing smart contracts. The L1 network is decentralized, meaning there are no intermediaries, and all transactions are recorded on a public ledger called the Block Explorer.
- Layer 2 (L2): This layer acts as an intermediary between the L1 network and the Ethereum Virtual Machine (EVM). It enables faster transaction processing times, lower fees, and improved scalability. The L2 network is also decentralized.
The Problem with Unverified Data
When using eth_call requests to access smart contracts on the L1 network, there are several potential issues that can arise:
- Data Tampering: A malicious actor could potentially tamper with the returned data from an eth_call request.
- Lack of Authentication: The Ethereum node or service providing the data may not be authenticated, making it difficult to verify its integrity.
Using Cryptographic Proofs for Verification
To address these issues, cryptographic proofs can be used to verify the results of eth_call requests on both L1 and L2 networks. Here are some ways you can implement this:
L1 Network
Using Web3.js with JSON-LD and GraphQL
Web3.js is a popular JavaScript library that enables interaction with the Ethereum blockchain. By using JSON-LD (JavaScript Object Notation for Linked Data) and GraphQL, you can create a decentralized application (dApp) on the L1 network that provides a secure way to access smart contracts.
“javascript
// Import required libraries
const Web3 = require('web3');
const jsonld = require('json-ld');
// Set up your Ethereum node or service
const web3 = new Web3(new Web3.providers.HttpProvider('
// Define a function to execute an eth_call request with JSON-LD and GraphQL
async function executeEthCall(request) {
// Create a GraphQL query using the json-ld library
const schema = new GraphQLSchema({
typeDefs: [
{
type: 'Query',
args: {
contractAddress: { type: 'String' },
contractFunctionName: { type: 'String' }
},
resolve: async (parent, args) => {
// Execute the eth_call request
const result = await web3.eth.call({
to: args.contractAddress,
data: args.contractFunctionName,
from: '0xYOUR_PROJECT_ID'
});
return JSON.parse(result);
}
}
]
});
// Use GraphQL'sexecuteQuerymethod to execute the query
const response = await schema.executeQuery({
query: {
query:
query {
contractAddress: ${args.contractAddress}
contractFunctionName: ${args.contractFunctionName}
}
`,
variables: args
}
});
return JSON.parse(response.data);
}
// Example usage:
const request = { contractAddress: ‘0xYOUR_CONTRACT_ADDRESS’, contractFunctionName: ‘myContractFunction’ };
executeEthCall(request).then((result) => console.