Architecting Secure Smart Contracts: Beyond Reentrancy

Smart contract security is often reduced to "avoiding reentrancy," but in 2024, the threat landscape is far more complex. As protocols grow in complexity, so do the attack vectors.

The Checks-Effects-Interactions Pattern

This remains the golden rule of Solidity development. Always validate inputs and conditions first (Checks), update state variables second (Effects), and interact with external contracts last (Interactions).

function withdraw(uint amount) public {
    // 1. Checks
    require(balances[msg.sender] >= amount, "Insufficient balance");
    
    // 2. Effects
    balances[msg.sender] -= amount;
    
    // 3. Interactions
    (bool success, ) = msg.sender.call{value: amount}("");
    require(success, "Transfer failed");
}

Access Control & Role Management

Hardcoding owner addresses is a recipe for disaster. Use standardized libraries like OpenZeppelin's AccessControl to manage granular permissions. Multi-sig wallets (like Gnosis Safe) should almost always govern high-value administrative functions.

Auditing Tools

Static analysis is your first line of defense. Tools like Slither and MythX automate the detection of common vulnerabilities. However, they are no substitute for a manual audit by a reputable firm.