The challenge of Smart Contract Security

The biggest challenge for smart contracts is the concept of call paths, which can be compared to various roads that external callers use to interact with a contract.

Each call path, much like every road, comes with its own set of potential issues, opening the door to various exploit opportunities. This complexity is compounded when you consider that modern smart contracts often incorporate multiple conditions, states, and entry points, essentially multiplying the number of 'roads' into the contract.

One of the critical hurdles in securing smart contracts is ensuring that every possible call path or 'road' is secure. However, as the number of these paths increases, so does the difficulty of securing them.

This is because each path may have its unique vulnerabilities, and these can intersect with vulnerabilities in other paths, creating a complex web of security challenges.

The problem is not only to secure each single call-path but it already starts by *identifying* all of them.

Junior auditors can easily miss specific call-paths, which leaves these completely unconsidered.

In my opinion, a strategic approach for developers is to aim for minimalism in their code. The principle here is straightforward: the fewer call paths there are, the smaller the attack surface.

By eliminating unnecessary call paths and ensuring that every entry point is absolutely essential, developers can significantly reduce the complexity of securing their contracts. This, in turn, makes it easier for auditors to thoroughly analyze each call path, enhancing the overall security of the smart contract.

In summary, the key to writing less vulnerable smart contracts lies in the disciplined practice of minimalism. By critically evaluating the necessity of each call path and eliminating the unnecessary, developers can greatly enhance the security of their contracts. This not only makes the auditor's job more manageable but also reduces the likelihood of costly exploits.