Verifying ed25519 signatures directly in a solana contract
As Blockchain Developers, we often face the Challenge of Integrating Various Signing Mechanisms Into Our Contracts. One such mechanism is ed25519, which allows for secure and efficient digital signatures using a cryptographic hash function and a private key. While there are existing solutions that enable verifying ed25519 signatures indirectly, placing the signature instruction and the calling instruction in a single transaction can be cumbersome.
In this article, we will explore an alternative approach to directly verify ed25519 signatures in a solana contract.
The Problem
Before diving into the solution, let’s address some common concerns:
* Transaction Size : Directly verifying ed25519 signatures requires a significant amount of storage space. By placing the signature instruction and calling instruction in a single transaction, we risk exceeding the maximum transaction size.
* Performance Overhead : Verifying each signature individual can introduce additional latency, which might not be acceptable for high-frequency trading or real-time applications.
The Solution
To address these concerns, we will implement a custom solution that uses the Verify Instruction to verify ed25519 signatures directly. This approximately approached consideration of the following aspects:
Signature Verification Functionality
We will create a dedicated function within our contract that verifies ed25519 signatures. This function will take the signature input and the hash of the contract’s storage as argument.
`Sol
Pragma Solidity ^0.8.0;
Contract Signatureverifier {
// … (other variables)
Function Verifyed25519Signature (
bytes32 _signature,
Address _from,
bytes Memory _storagehash,
uint256 _gaslimit
) Public View Returns (Bool) {
// Verify the Signature Using ED25519
Require ED25519 Verify (_signature, _from, _storagehash, _gaslimit);
Return True;
}
}
`
ED25519 LIBRARY Integration
We will use the Solana-Verify Library to perform the actual verification. This library provides a high-level interface for verifying signatures using ed25519.
`Solidity
Pragma Solidity ^0.8.0;
Library Solanaverify {
Function Verify (Uint256 _hash) internal view returns (bool);
}
Contract Signatureverifier {
Using solanaverify.sol (solanaverify);
// … (other variables)
Function Verifyed25519Signature (
bytes32 _signature,
Address _from,
_storagehash bytes
) Public View Returns (Bool) {
Return verify (_signature, _from, _storagehash);
}
}
`
Transaction Structure
To avoid exceeding the Maximum Transaction Size Limit, We Will Structure Our Contract As Follow:
`Solidity
Pragma Solidity ^0.8.0;
Contract Signatureverifier {
// … (other variables)
bytes32 Public Signature;
Address public from;
bytes Memory Storagehash;
Function Setsignature (bytes32 _signature) public {
Require ED25519 Verify (_signature, frame, storagehash, 100000); // 100k gas
signature = _signature;
from = address (…);
storagehash = _storagehash;
}
Function Verifyed25519Signature (
bytes32 _signature,
Address _from,
_storagehash bytes
) Public View Returns (Bool) {
Require ED25519 Verify (_signature, _from, _storagehash, 100000); // 100k gas
Return True;
}
}
`
USage Example
To use this solutions, create a new contract and import the Signatureverifier 'Contract.
Sol
Pragma Solidity ^0.8.