How do you avoid security risks when developing dApps on Ethereum?

1 Test your code thoroughly

One of the most important steps to avoid security risks is to test your code thoroughly before deploying it to the mainnet. You can use various tools and frameworks, such as Truffle, Hardhat, Ganache, and Remix, to create local or simulated environments where you can run your code and check its functionality, performance, and security. You can also use automated testing tools, such as Mocha, Chai, or Waffle, to write unit tests, integration tests, and end-to-end tests for your smart contracts and dApps. Testing your code can help you identify and fix bugs, errors, vulnerabilities, and logic flaws before they cause any damage.

2 Follow coding standards and best practices

In order to avoid security risks, it is important to follow coding standards and best practices for smart contracts and dApps. Solidity is the most popular programming language for Ethereum, but other languages, such as Vyper, LLL, or Yul, can also be used. When writing smart contracts, you should adhere to some general principles; for example, use the latest and stable version of the compiler and libraries, use clear and consistent naming conventions and comments, use modifiers, events, and error handling mechanisms. Additionally, you should avoid using loops or recursion that can lead to high gas costs or out-of-gas errors. External calls or delegate calls should also be avoided as they can expose your contract to reentrancy attacks or malicious code injection. To protect your contract further, you can employ security patterns such as checks-effects-interactions, withdrawal pattern, circuit breaker, and rate limiter. Lastly, always avoid using unsafe or deprecated functions like tx.origin, blockhash, or selfdestruct.

3 Audit your code by experts

Even if you test your code thoroughly and follow coding standards and best practices, you may still miss some security issues or vulnerabilities that can be exploited by hackers or malicious actors. Therefore, it is highly recommended that you audit your code by experts before deploying it to the mainnet. An audit is a process of reviewing your code by a third-party or independent team of security experts who can verify its quality, functionality, and security. An audit can help you find and fix any potential problems, bugs, or weaknesses in your code, as well as provide you with feedback and suggestions for improvement. You can find various platforms and services that offer smart contract and dApp auditing, such as OpenZeppelin, ConsenSys Diligence, Quantstamp, or CertiK.

4 Use formal verification tools

Another way to avoid security risks is to use formal verification tools for your smart contracts and dApps. Formal verification is a method of proving or disproving the correctness of your code by using mathematical logic and techniques. Formal verification can help you ensure that your code behaves as intended and meets its specifications, as well as detect and prevent any errors, bugs, or vulnerabilities that may not be caught by testing or auditing. Formal verification can also help you optimize your code and reduce its gas costs. However, formal verification can be complex, time-consuming, and expensive, so it may not be suitable for every project or scenario. You can use various tools and frameworks for formal verification, such as K Framework, Coq, Dafny, or VeriSol.

5 Monitor and update your code regularly

Finally, to avoid security risks, you should monitor and update your code regularly after deploying it to the mainnet. You should keep track of your smart contracts and dApps performance, usage, and security, as well as any changes or updates in the Ethereum network, protocols, or standards. You should also be aware of any new or emerging threats, attacks, or vulnerabilities that may affect your code or data. You can use various tools and services to monitor and update your code, such as Etherscan, Tenderly, Alchemy, or Infura. You should also consider using upgradeable smart contracts or proxy contracts that allow you to modify or replace your code without affecting its functionality or state. However, you should also be careful not to compromise your code's decentralization, transparency, or immutability.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?