QVM vs EVM

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

library QuantumSig {
    address constant PQ_VERIFY = address(0x0b);

    /// @notice Verify a post-quantum signature and return the signer address.
    /// @param digest    The 32-byte Keccak-256 digest that was signed.
    /// @param publicKey The signer's post-quantum public key.
    /// @param signature The post-quantum signature over `digest`.
    /// @return signer   The 20-byte address derived from `publicKey`, or 0x0 on failure.
    function recover(
        bytes32 digest,
        bytes calldata publicKey,
        bytes calldata signature
    ) internal view returns (address signer) {
        bytes memory input = abi.encodePacked(digest, publicKey, signature);
        (bool ok, bytes memory out) = PQ_VERIFY.staticcall(input);
        if (!ok || out.length != 32) {
            return address(0);
        }
        // The precompile returns Keccak256(publicKey) padded to 32 bytes;
        // the address is the low 20 bytes.
        signer = address(uint160(uint256(bytes32(out))));
    }
}

// Before (EVM):
// address signer = ecrecover(digest, v, r, s);

// After (QVM):
address signer = QuantumSig.recover(digest, publicKey, signature);
require(signer == expected, "bad signature");